Damage Prevention and Control Methods

Prairie rattlesnake, Crotalus viridis viridis

An occasional single poisonous snake can be destroyed if one has enough determination. In areas where the habitat is favorable for rattlesnakes, copperheads, or water moccasins, a significant reduction in their population density may be difficult. In snake country, most people learn to “keep their eyes open” and be cautious.

Exclusion

When feasible, the most effective way for a homeowner to protect a child’s play area from rattlesnakes is to construct a rattlesnake-proof fence around it. The fencing must be tight. If wire mesh is used, it should be 1/4-inch (0.6-cm) mesh and about 3 feet (1 m) high. Bury the bottom 3 or 4 inches (8 or 10 cm) or bend outward 3 or more inches of the base of the wire to discourage other animals from digging under the fence. Put the stakes on the inside and install a gate that is tight-fitting at the sides and bottom, equipped with a self-closing spring. The benefit of the fence will be lost if wood, junk, or thick vegetation accumulates against the outside of the fence. Vegetation that has ground-level foliage also provides attractive hiding places for rattlesnakes, so it should be removed or properly pruned. Tight-fitting doors will prevent snakes from entering outbuildings. The foundations of all buildings should be sealed or tightly screened with 1/4-inch (0.6-cm) wire mesh to keep out snakes.

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 effectiveness of removing the prey of snakes, effective, sustained rodent control will reduce the attractiveness of a rural residence or other facility to rattlesnakes. Snakes will not remain in habitat made less favorable for them. Hiding places under buildings, piles of debris, ordense vegetation should be removed. Hay barns and feed storage areas that encourage rodents will attract rattlers.

Frightening

No methods are known that will frighten rattlesnakes. Sounds certainly will not work because snakes are deaf.

Repellents

Many potential snake repellents have been researched, only to be found ineffective. All species of snakes are likely to cross a strip of repellent substance if they want to get to the other side. Dr. T’sTM Snake-A-Way®, a mixture of sulphur-naphthalene, has been registered by EPA; however, its registration in California was denied as of July 1991, because required data was not submitted. A Y-shaped laboratory enclosure that provided rattlers with a choice of crawling into a tunnel with odor or one free of odor showed they usually chose the passage free of odor. No field test data is available. To be of practical use, the odor of a snake repellent must not be too objectionable to people.

Toxicants

No effective toxicant is registered for the control of rattlesnakes. When rodents were poisoned with various rodenticides and then fed to rattle-snakes, the snakes were not affected. Apparently, digestion is too slow for the toxicants to have an effect on snakes.

Fumigants

It may be possible to kill rattlesnakes in burrows and rock dens with toxic gas, although this is not a very practical method. Calcium cyanide is a chemical frequently recommended, but no lethal gas has had good success because snakes have such a slow rate of metabolism, especially when in hibernation. In addition, susceptible non-target species in the burrows or dens may become victims.

In the spring and early summer, when hibernating snakes are about to emerge, gasoline poured down a bur-row or into a den will drive the snakes out. As the snakes exit they can be clubbed, shot, or captured alive with snake tongs that secure a snake at its neck. If transported in a bag, tie the top securely. Many snake hunters push a hose down a burrow and after listening to confirm that rattlesnakes are present, pour 1 to 2 ounces (30 to 60 ml) of gasoline into a funnel on the hose and then blow on the hose. This technique seems quite effective for seasonally reducing rattlesnake numbers, but it may be lethal to nontarget animals including nonpoisonous and beneficial snakes. To be effective, community-wide campaigns should extend over several days, since many snakes may escape into holes or crevices. Snake hunters should wear protective clothing such as pants, heavy gloves, and boots.

Trapping

Figure 4. A fish-type funnel trap of 1/4-inch hardware cloth attached to an inward-sloping drift fence 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.

Various combinations of fencing and traps at known rattlesnake dens can be very successful if one is trying to collect rattlesnakes, because in some localities several hundred rattlesnakes may occupy the same den. If all but one opening can be blocked, it is then quite simple to pipe or otherwise channel the emerging rattlesnakes into a large oil drum or other receptacle. If it is not possible to find all den openings, inward-sloping drift fences of 1/4-inch (0.6-cm) hardware cloth mesh, 1 or 2 feet (0.5 m) high, with fish-type funnel traps (Fig. 4) will suffice. The inward sloping funnel makes it difficult for the snakes to escape. If a wooden nest box is attached to one side of these traps, the snakes will usually hide in the box and not spend as much time trying to escape. Drift-fence funnel traps also catch many other animals. Therefore, this control method requires daily inspection and usually is not very practical except at dens.

Figure 5. A glue trap to catch rattlesnakes can be made by attaching three to six rodent glue traps to a wooden board.

Glue boards are useful for trapping rattlesnakes that are in or under buildings (Knight 1986). To trap rattle-snakes, use a plywood board approximately 24 x 16 inches (61 x 41 cm). Securely tack a 6 x 12-inch (15 x 30-cm) rodent glue trap (or use bulk glue to make a similar-sized glue patch) to the plywood (Fig. 5). Place the board against a wall, as this is where snakes are likely to travel. The rattlesnake will become stuck while attempting to cross the board. Do not place the board near any objects (pipes, beams) that the snake can use for leverage in attempting to free itself.

The glue trap can be removed easily using a long stick or pole with a hook or by an attached rope if a hole is drilled through the plywood board. Animals trapped in the glue can be removed with the aid of vegetable oil, which counteracts the adhesive.

Do not use glue boards outdoors or in any location where they are likely to catch pets or desirable nontarget wild-life. The glue can be quite messy and is difficult to remove from animals.

Shooting

A shotgun has often been used to eliminate individual rattlesnakes around a rural homestead. Similarly, a pistol loaded with birdshot is very effective at close range. Shooting is not considered effective for reducing large populations.

Other Methods

Dynamite blasting of known dens is dangerous and has questionable advantages. There is no way to know what kinds and how many snakes have been killed, and the blast may create an even better den for future rattlesnakes.

Rattlesnakes have natural predators, but the predators are not likely to help much in controlling rattlesnake populations. Some dogs, especially if they have experienced a snake bite, become excellent guards for children. They will bark when a snake is discovered, and many can kill rattlesnakes as well. Domestic geese and turkeys may also help, by acting as an alarm and by frightening snakes. Hogs do not provide practical protection around a homestead.

Snake Bite

The best protection for humans when traveling in snake country is common sense in choosing protective foot and leg wear. When climbing, one should beware of putting a hand up over rocks. Rattlesnakes might be waiting there for a rodent, and the warmth in a hand may cause the snake to strike reflexively. Care should be taken at night, when snakes are more active, and the chance of stepping on a snake is greater. Fortunately, rattlesnakes try to avoid people.

The best first aid for a poisonous snake bite is to seek immediate medical care. Time is tissue. Keep the victim calm, warm, reassured, and bite wound on level with heart (if possible). Do not drink alcohol or use ice, cold packs, or freon spray to treat the snake bite or cut the wound, as was once recommended. Remove all constrictive clothing and jewelry. If, and only if, medical help is more than 4 hours away, then you may consider using a "plunger-extractor system."

The causes of human death from rattlesnake venom are varied, but usually occur from extended hypotension and cardiopulmonary arrest. Usually within a few minutes after being struck the victim will experience pain and swelling at the wound site.