RATTLESNAKES (Crotalus Viridis Viridis)

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln

The Handbook: Prevention and Control of Wildlife Damage Management, Internet Center Wildlife Damage for

January 1994

RATTLESNAKES (Crotalus viridis viridis)

Walter E. Howard Professor Emeritus of Wildlife Biology and Vertebrate Ecology, Department of Wildlife, Fisheries and Conservation Biology, University of California, Davis, California 95616

Follow this and additional works at: https://digitalcommons.unl.edu/icwdmhandbook

Part of the Environmental Sciences Commons

Howard, Walter E., "RATTLESNAKES (Crotalus viridis viridis)" (1994). The Handbook: Prevention and Control of Wildlife Damage. 81. https://digitalcommons.unl.edu/icwdmhandbook/81

This Article is brought to you for free and open access by the Wildlife Damage Management, Internet Center for at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in The Handbook: Prevention and Control of Wildlife Damage by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Walter E. Howard Professor Emeritus of Wildlife Biology and Vertebrate Ecology RATTLESNAKES Department of Wildlife, Fisheries and Conservation Biology University of California Davis, California 95616

Fig. 1. Prairie rattlesnake, Crotalus viridis viridis

Introduction Trapping Damage Prevention and Rattlesnakes are distinctly American Control Methods* Effective in some situations when serpents. They all have a jointed rattle properly placed. at the tip of the tail, except for one rare Exclusion Glue boards are useful in removing species on an island off the Mexican Construct a snake-proof fence around rattlesnakes from buildings. coast. This chapter concerns the genus areas of human activity. Crotalus, of the pit viper family Shooting Crotalidae, suborder Serpentes. Since Seal entrances to buildings and snakes evolved from lizards, both structures. Effective where safe. groups make up the order Squamata. Habitat Modification Other Methods This article describes the characteris- Eliminate shelter for snakes. Organized snake hunts may be tics of the common species of rattle- successful in spring or early snakes that belong to the genus Control rodents; they attract snakes. summer. Crotalus. These include the eastern Repellents Snake Bite diamondback, (C. adamanteus); the None are available. western diamond (back) rattlesnake, Wear protective clothing and be (C. atrox); the red diamond rattlesnake, Toxicants careful when climbing and walking. (C. ruber); the Mohave rattlesnake, None are available. If a bite occurs, keep the victim calm, (C. scutulatus); the sidewinder, (C. warm, and reassured. Seek medical ceraster); timber rattlesnake, (C. Fumigants attention immediately. horridus); three subspecies of the west- Generally not effective in dens. ern rattlesnake, (C. viridis): the prairie rattlesnake (C. v. viridis); the Great Basin rattlesnake (C. v. lutosus); and *Information pertains to other poisonous snakes. the Pacific rattlesnake (C. v. oreganus).

PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994 Cooperative Extension Division Institute of Agriculture and Natural Resources University of Nebraska - Lincoln United States Department of Agriculture Animal and Plant Health Inspection Service Animal Damage Control F-21 Great Plains Agricultural Council Wildlife Committee There are 15 species of rattlesnakes in Elliptical eye pupil the United States and 25 in Mexico. Other front-fanged poisonous snakes of the Crotalidae family, which are not Nostril included in this discussion, are the massasauga and pigmy rattlesnakes, both of the genus Sistrurus. Also not included are two snakes that do not have rattles, hence are not called rattlesnakes: the water moccasin or cotton- Loreal pit opens forward mouth, and the copperhead, both of the genus Agkistrodon. Two other gen- Fig. 2. Rattlesnake head showing “cat-eye” elliptical pupil and location of the large loreal pit, characteristic of pit vipers. era of poisonous snakes in North America are coral snakes (Micrurus black, chalky white, dull red, and olive or cannot be tracked after being struck. and Micruroides) of the family green. Many have diamond, chevron, One male rattler captured in the field Elapidae. or blotched markings on their backs had consumed 123% of its weight, but and sides. young rattlers frequently die due to Identification lack of food. Domestically raised rat- Range and Habitat tlesnakes will survive when fed only Rattlesnakes are usually identified once a year, but in the field, snakes by their warning rattle — a hiss or usually feed more than once, depend- Rattlesnakes occur only in North and buzz — made by the rattles at the tip ing on the size of prey consumed. A South America and range from sea of their tails. A rattlesnake is born with snake may kill several prey, one after level to perhaps 11,000 feet (over 3,000 a button, or rattler, and acquires a new another, and of different species. m) in California and 14,000 feet (4,000 rattle section each time it molts. Rattle- When rodents and rabbits are struck, m) in Mexico, although they are not snakes also are distinguished by hav- the prey is immediately released. The abundant at the higher elevations. ing rather flattened, triangular heads. snake then uses its tongue to track the They are found throughout the Great The heads of all Crotalus rattlesnakes prey to where it has died. Plains region and most of the United are about twice as wide as their necks. States, from deserts to dense forests Digestion is quite slow and usually no Only pit vipers possess this head con- and from sea level to fairly high moun- bones remain in the feces, called figuration; coral snakes do not. tains. They need good cover so they “scats.” Hair, feathers, and sometimes Rattlesnakes belong to the pit viper can retreat from the sun. Rattlers are teeth, however, can usually be identi- family Crotalidae, so named because common in rough terrain and wher- fied in scats. Rattlesnakes use very all possess visible loreal pits, or lateral ever rodents are abundant. little energy except when active, and heat sensory organs, between eye and they probably are active for less than nostril on each side of the head (Fig. 2). Food Habits 10% of their lives. They are not very These heat sensory pits are not present active unless food is scarce. They store in true vipers, which do not occur in Young or small species of rodents much fat in their bodies, which can last the Western Hemisphere. The facial comprise the bulk of the food supply them for long periods. pits enable rattlesnakes to seek out and for most rattlesnakes. Larger rattlers strike, even in darkness, warm objects may capture and consume squirrels, General Biology, such as small animal prey, as well as prairie dogs, wood rats, cottontails, Reproduction, and larger animals that could be a threat. and young jackrabbits. Occasionally, The vertically elliptical eye pupils, or even small carnivores like weasels and Behavior “cat eyes,” are also a characteristic of skunks are taken. Ground-nesting rattlesnakes (Fig. 2). Identifying a dead birds and bird eggs can also make up When a rattlesnake strikes its prey or rattler whose rattles are missing can be an appreciable amount of the diet of enemy, the paired fangs unfold from done by looking at the snake’s scales some rattlers. Lizards are frequently the roof of its mouth. Prior to the on the underside in the short region taken by rattlers, especially in the completion of the forward strike between the vent and the tip of the tail. Southwest. The smaller species of motion, the fangs become fully erect at If the scales are divided down the cen- rattlesnakes and young rattlesnakes the outer tip of the upper jaw. The ter, the snake is harmless. The scales regularly feed on lizards and amphib- erectile fangs are hollow and work like on rattlesnakes are not divided. ians. hypodermic needles to inject a modified saliva, the venom, into the Rattlesnakes come in a great variety of Rattlesnakes consume about 40% of prey. Rattlesnakes can regulate the colors, depending on the species and their own body weight each year. amount of venom they inject when stage of molt. Most rattlers are various Many prey are killed but not eaten by they strike. shades of brown, tan, yellow, gray, rattlesnakes because they are too large

F-22 Mature fangs generally are shed sev- Opening to hollow eral times a season. They may become fang is a groove on outer surface embedded in the prey and may even be swallowed with the prey. When one mature fang in a pair is lost, it will soon be replaced by another functional mature fang. A series of developing Replacement fangs fangs are located directly behind one in sheath another in the same sheath at the roof and outer tip of the mouth (Fig. 3). If a Right venom newly replaced fang is artificially gland removed, it may require weeks or longer before another replacement will Teeth be fully effective. One fang can func- tion, however, while the other in the pair is being replaced. Fangs that get stuck in a person’s boot are not very dangerous; they cannot contain much venom since they serve only as a hollow needle. The external opening of the hollow fang is a groove on the outside of the fang, set slightly back from the tip to prevent it from becoming plugged by tissue from the prey (Fig. 3). Fig. 3. Head of a rattlesnake in striking position. Supple- Rattlesnakes cannot spit venom, but mentary fangs are covered by a sheath of tissue. Each the impact of a strike against an object fang is located in a double socket. Replacement fangs appear in what are currently empty sockets. can squeeze the venom gland, located in the roof of the mouth, and venom may be squirted. This can happen when a rattler strikes the end of a stick long as a year. During summer, preg- scopic particles from the environment pointed at it, or the wire mesh of a nant females usually do not feed, so to sensory cells in pits at the roof of the snake trap. The venom is released few are ever captured that contain mouth. A rattlesnake uses these pits to involuntarily if sufficient pressure is eggs about to hatch. The young are track prey it has struck and to gather exerted, as occurs when venom is arti- born in the fall. Most rattlesnakes are information about its environment. mature in 3 years, but may require ficially “milked” from live snakes. Snakes have a large number of ribs more time in northerly areas. Rattle- Such venom is dangerous only if it and vertebrae with ball-and-socket snakes may not produce young every gets into an open wound. Always joints. Each rib is joined to one of the year. wear protective clothing when han- scales on the snake’s underside. The dling rattlesnakes. The sex of a rattlesnake is not easy to snake accomplishes its smooth flowing Female rattlesnakes are ovoviviparous. determine. Even though the tail of the glide by hooking the ground with its That is, they produce eggs that are re- rattlesnake (the distance between the scales, which are then given a back- tained, grow, and hatch internally. The vent and the rattles) is quite short, it is ward push from the ribs. Rattlesnakes young of most species of rattlesnakes much longer in males than in females often look much larger when seen live are 6 to 8 inches (15 to 20 cm) when of the same size. The paired than after they have been killed. This born. They are born with a single rattle hemipenises of male snakes are not happens because their right lung or button, fangs, and venom. They can visible except during mating, when extends almost the full length of the strike within minutes, but being so one of these paired hollow organs is tubular body, and when the snakes small, they are not very dangerous. turned inside out and extruded from inhale they can appear much fatter and Average broods consist of 5 to 12 the cloaca. If both are extruded artifi- more threatening. The expulsion of the young, but sometimes twice as many cially, they appear like two forked, air can produce a hiss. stumpy legs. may be produced. Rattlesnakes, like other snakes, peri- The breeding season lasts about 2 Snakes never close their eyes, since odically shed their skin. When the new months in the spring when the snakes they have no eyelids. They are deaf, skin underneath is formed, the snake emerge from hibernation. Sperm is but can detect vibrations. They have a rubs its snout against a stone, twig, or thought to survive in the female as good sense of smell and vision, and rough surface until a hole is worn their forked tongues transport micro- through. After it works its head free,

F-23 the snake contracts its muscles rhyth- If a rattlesnake has just been killed by usually apparent on livestock that are mically, pushing, pulling, and rubbing, cutting off its head, it can still bare its bitten (see Wade and Bowns 1982, until it can crawl out of the old skin, fangs and bite. The heat sensory pits pages 32 and 34 in the Damage Identi- which peels off like an inverted stock- will still be functioning, and the fication section of this book). ing. Each molt produces a new rattle. warmth of a hand will activate the Some rattles usually break off from striking reflex. The head cannot strike, Legal Status older snakes. Even if no rattles have but it can bite and inflict venom. The been lost, they do not indicate exact reflex no longer exists after a few min- Most species of rattlesnakes are not con- age because several rattles may be pro- utes, or as long as an hour or more if it sidered threatened or endangered. Since duced in one season. is cool, as rigor mortis sets in. they are potentially dangerous, there has not been much support for protecting Even though the optimum tempera- them except in national parks and pre- o Damage and Damage ture for rattlesnakes is around 77 to serves. However, since there are state o o o 89 F (25 to 32 C), the greatest period Identification and local restrictions, contact local wild- of activity is spring, when they come life agencies for more information. out of hibernation and are seeking The greatest danger to humans from food. If lizards are active, be alert for rattlesnakes is that small children may rattlesnakes. The activity period for be struck while rolling and tumbling in Damage Prevention and rattlers can vary from about 10 months the grass. Only about 1,000 people are Control Methods or so in warm southern regions to per- bitten and less than a dozen people die An occasional single poisonous snake haps less than 5 months in the north from rattlesnake venom each year in can be destroyed if one has enough and at high elevations. Depending the United States. Nevertheless, it is a determination. In areas where the upon availability of good, dry denning most unpleasant experience to be habitat is favorable for rattlesnakes, sites below the frost line, rattlesnakes struck. The venom, a toxic enzyme copperheads, or water moccasins, a may hibernate alone or in small num- synthesized in the snake’s venom significant reduction in their popula- bers. However, sometimes they den in glands, causes tissue damage, as it tion density may be difficult. In snake large groups of several hundred in tends to quickly tenderize its prey. country, most people learn to “keep abandoned prairie dog burrows or When known to be abundant, rattle- their eyes open” and be cautious. rock caverns, where they lie torpid in snakes detract from the enjoyment of groups or “balls.” All dens must be outdoor activities. The human fear of Exclusion deep enough so the temperature is not rattlesnakes is much greater than the When feasible, the most effective way affected by occasional warm days. If hazard, however, and many harmless for a homeowner to protect a child’s not, the snakes might emerge too early snakes inadvertently get killed as a re- play area from rattlesnakes is to con- in spring only to become sluggish and sult. Death from a rattlesnake bite is struct a rattlesnake-proof fence around vulnerable should the weather again rare and the chance of being bitten in it. The fencing must be tight. If wire turn cold. Since snakes are cold- the field is extremely small. mesh is used, it should be 1/4-inch blooded animals and their body tem- Experienced livestock operators and (0.6-cm) mesh and about 3 feet (1 m) perature is altered by air temperature, farmers usually can identify rattle- high. Bury the bottom 3 or 4 inches (8 refrigeration makes them sluggish and snake bites on people or on livestock or 10 cm) or bend outward 3 or more easy to handle for displaying. without much difficulty, even if they inches of the base of the wire to dis- Rattlesnakes usually see humans be- did not witness the strike. A rattle- courage other animals from digging fore humans see them, or they detect snake bite results in almost immediate under the fence. Put the stakes on the soil vibrations made by walking. They swelling, darkening of tissue to a dark inside and install a gate that is tight- coil for protection, but they can strike blue-black color, a tingling sensation, fitting at the sides and bottom, only from a third to a half of their and nausea. Bites will also reveal two equipped with a self-closing spring. body length. Rattlers rely on surprise fang marks in addition to other teeth The benefit of the fence will be lost if to strike prey. Once a prey has been marks (all snakes have teeth; only pit wood, junk, or thick vegetation struck, but not killed, it is unlikely that vipers have fangs too). Rattlesnakes of- accumulates against the outside of the it will be struck again. Experienced ten bite livestock on the nose or head fence. Vegetation that has ground-level rodents and dogs can evade rattle- as the animals attempt to investigate foliage also provides attractive hiding snake strikes. them. Sheep, in particular, may crowd places for rattlesnakes, so it should be together in shaded areas near water removed or properly pruned. Tight- Rattlesnakes may appear quite aggres- during midday. As a consequence, fitting doors will prevent snakes from sive if exposed to warm sunshine. they also frequently are bitten on the entering outbuildings. The foundations Since they have no effective cooling legs or lower body when pushed close of all buildings should be sealed or mechanism, they may die from heat to snakes. Fang marks and tissue dis- tightly screened with 1/4-inch (0.6-cm) stroke if kept in the sun on a hot day coloration that follows in the major wire mesh to keep out snakes. much longer than 15 or 20 minutes. blood vessels from the bite area are

F-24 Habitat Modification It is always desirable to use nonlethal biological means of control when feasible. Although good quantified data are not available to evaluate the effec- tiveness of removing the prey of snakes, effective, sustained rodent control will reduce the attractiveness of a rural resi- dence or other facility to rattlesnakes. Snakes will not remain in habitat made less favorable for them. Hiding places Funnel under buildings, piles of debris, or dense vegetation should be removed. Hay barns and feed storage areas that encour- DriftDrift fenceFence age rodents will attract rattlers. Frightening Fig. 4. A fish-type funnel trap of 1/4-inch hardware cloth attached to an inward-sloping drift fence No methods are known that will of the same wire mesh can be useful in trapping snakes as they emerge from a multi-opening den. Escape will be reduced if a wooden nest box is attached to the funnel trap. frighten rattlesnakes. Sounds certainly will not work because snakes are deaf. Repellents but no lethal gas has had good success localities several hundred rattlesnakes because snakes have such a slow rate may occupy the same den. If all but Many potential snake repellents have of metabolism, especially when in hi- one opening can be blocked, it is then been researched, only to be found inef- bernation. In addition, susceptible non- quite simple to pipe or otherwise chan- fective. All species of snakes are likely target species in the burrows or dens nel the emerging rattlesnakes into a to cross a strip of repellent substance if may become victims. large oil drum or other receptacle. If it they want to get to the other side. is not possible to find all den openings, In the spring and early summer, when TM inward-sloping drift fences of 1/4-inch Dr. T’s Snake-A-Way®, a mixture of hibernating snakes are about to (0.6-cm) hardware cloth mesh, 1 or 2 sulphur-naphthalene, has been registered emerge, gasoline poured down a bur- feet (0.5 m) high, with fish-type funnel by EPA; however, its registration in Cali- row or into a den will drive the snakes traps (Fig. 4) will suffice. The inward fornia was denied as of July 1991, out. As the snakes exit they can be sloping funnel makes it difficult for the because required data was not submit- clubbed, shot, or captured alive with snakes to escape. If a wooden nestbox ted. A Y-shaped laboratory enclosure snake tongs that secure a snake at its is attached to one side of these traps, that provided rattlers with a choice of neck. If transported in a bag, tie the top the snakes will usually hide in the box crawling into a tunnel with odor or one securely. Many snake hunters push a and not spend as much time trying to free of odor showed they usually chose hose down a burrow and after listen- escape. Drift-fence funnel traps also the passage free of odor. No field test ing to confirm that rattlesnakes are catch many other animals. Therefore, data is available. To be of practical use, present, pour 1 to 2 ounces (30 to 60 this control method requires daily the odor of a snake repellent must not be ml) of gasoline into a funnel on the inspection and usually is not very too objectionable to people. hose and then blow on the hose. This practical except at dens. Toxicants technique seems quite effective for sea- sonally reducing rattlesnake numbers, Glue boards are useful for trapping No effective toxicant is registered for but it may be lethal to nontarget ani- rattlesnakes that are in or under build- the control of rattlesnakes. When mals including nonpoisonous and ings (Knight 1986). To trap rattle- rodents were poisoned with various beneficial snakes. To be effective, com- snakes, use a plywood board rodenticides and then fed to rattle- munity-wide campaigns should approximately 24 x 16 inches (61 x 41 snakes, the snakes were not affected. extend over several days, since many cm). Securely tack a 6 x 12-inch (15 x Apparently, digestion is too slow for snakes may escape into holes or 30-cm) rodent glue trap (or use bulk the toxicants to have an effect on crevices. Snake hunters should wear glue to make a similar-sized glue snakes. protective clothing such as pants, patch) to the plywood (Fig. 5). Place Fumigants heavy gloves, and boots. the board against a wall, as this is Trapping where snakes are likely to travel. The It may be possible to kill rattlesnakes rattlesnake will become stuck while in burrows and rock dens with toxic Various combinations of fencing and attempting to cross the board. Do not gas, although this is not a very practi- traps at known rattlesnake dens can be place the board near any objects cal method. Calcium cyanide is a very successful if one is trying to col- (pipes, beams) that the snake can use chemical frequently recommended, lect rattlesnakes, because in some for leverage in attempting to free itself.

F-25 24 leg wear. When climbing, one should Acknowledgments beware of putting a hand up over rocks. Rattlesnakes might be waiting Figures 1 through 3 by Emily Oseas Routman. 16 there for a rodent, and the warmth in a Figures 4 and 5 by Jill Sack Johnson. hand may cause the snake to strike reflexively. Care should be taken at For Additional night, when snakes are more active, Information Fig. 5. A glue trap to catch rattlesnakes can be and the chance of stepping on a snake made by attaching three to six rodent glue traps is greater. Fortunately, rattlesnakes try Dunkle, T. 1981. A perfect serpent. Science 81 to a wooden board. to avoid people. 2:30-35. Duvall, D., M. B. King, and K. J. Gutzwiller. The glue trap can be removed easily The best first aid for a poisonous snake using a long stick or pole with a hook 1985. Behavioral ecology and ethology of bite is to seek immediate medical care the prairie rattlesnake. Natl. Geogr. Res. or by an attached rope if a hole is and to keep the victim calm, warm, 1:80-111. drilled through the plywood board. and reassured. Do not drink alcohol or Dolbeer, R. A., N. R. Holler, and D. W. Animals trapped in the glue can be use ice, cold packs, or freon spray to Hawthorne. 1994. Identification and control removed with the aid of vegetable oil, treat the snake bite or cut the wound, of wildlife damage. Pages 474-506 in T. A. which counteracts the adhesive. as was once recommended. Bookhout ed. Research and management techniques for wildlife and habitats. The Do not use glue boards outdoors or in If a victim of snake bite is several hours Wildl. Soc. Bethesda, Maryland. any location where they are likely to from a car and medical aid, apply a light Kilmon, J., and H. Shelton. 1981. Rattlesnakes in catch pets or desirable nontarget wild- constricting cloth or other band on the America. Shelton Press, Sweetwater, Texas. life. The glue can be quite messy and is bitten limb, 2 to 4 inches (5 to 10 cm) from 234 pp. difficult to remove from animals. the bite and between bite and heart. Klauber, L. M. 1972. Rattlesnakes: their habits, life Shooting Make sure it is not as tight as a tourni- histories, and influence on mankind, 2 vols. Univ. California Press, Berkeley. 1533 pp. quet. It should be easy to insert a finger A shotgun has often been used to elimi- under the band. Loosen it if swelling Klauber, L. M. 1982. Rattlesnakes: their habitats, nate individual rattlesnakes around a occurs. Apply suction at the wound for life histories, and influence on mankind. rural homestead. Similarly, a pistol Abridged by K. H. McClung. Univ. at least 3/4 of an hour by mouth (if no California Press, Berkeley. 350 pp. loaded with birdshot is very effective at mouth sores), or with a snake bite kit, but Knight, J. E. 1986. A humane method for close range. Shooting is not considered again, only if medical assistance is sev- effective for reducing large populations. removing snakes from dwellings. Wildl. Soc. eral hours away. Bull. 14:301-303. Other Methods The causes of human death from Marsh, R. E., and W. E. Howard. 1982. Dynamite blasting of known dens is rattlesnake venom are varied, but usu- Vertebrate pests. Pages 791-861 in A. Maillis, ed. Handbook of pest control, 6th ed. dangerous and has questionable ally occur from extended hypotension Franzak and Foster Co., Cleveland, Ohio. advantages. There is no way to know and cardiopulmonary arrest. Usually 1001 pp. within a few minutes after being what kinds and how many snakes Pinney, R. 1981. The snake book. Doubleday & have been killed, and the blast may struck the victim will experience pain Co., New York. 248 pp. create an even better den for future and swelling at the wound site. San Julian, G. J., and D. K. Woodward. 1986. rattlesnakes. What you wanted to know about all you Economics of Damage and ever heard concerning snake repellents. Rattlesnakes have natural predators, Control Proc. Eastern Wildl. Damage Control Conf. but the predators are not likely to help 2:243-248. much in controlling rattlesnake popu- The greatest economic loss to humans Seigle, R. A., J. T. Collins, and S. S. Novak. 1987. lations. Some dogs, especially if they from rattlesnakes comes from the Snakes: ecology and evolutionary biology. have experienced a snake bite, become number of domestic livestock and pets Macmillan Publ. Co., New York. 529 pp. excellent guards for children. They will that are killed. Horses and cattle are Story, K. 1987. Snakes: separating fact bark when a snake is discovered, and most frequently struck in the head from fantasy. Pest Control Technol. many can kill rattlesnakes as well. while grazing. Some have claimed 15(11):54,55,58,60. Domestic geese and turkeys may also that rattlesnakes benefit ranchers by Wade, D. A., and J. E. Bowns. 1982. Procedures help, by acting as an alarm and by the number of rodents they eat, but for evaluating predation on livestock and frightening snakes. Hogs do not pro- current predator-prey theory dis- wildlife. Bull. No. B-1429, Texas A & M vide practical protection around a counts this. It is very doubtful that Univ., College Station. 42 pp. homestead. snakes have much effect on the density of rodents. Snake Bite Editors The commercial value of rattlesnakes Scott E. Hygnstrom The best protection for humans when consists of the venom, rattles, skins Robert M. Timm traveling in snake country is common Gary E. Larson and, to a limited degree, the meat. sense in choosing protective foot and

F-26