BIOLOGY AND BEHAVIOR Snakes are reptiles. They have scales, are exothermic and must rely on external sources to control their body temperature, and like most reptiles they lay eggs. Snakes often shed their skin more than once each year to accommodate their growing bodies. Snakes must avoid extremes in temperatures and they prefer to hunt during mild conditions. Their forked tongues and heat sensitive facial pits are used to determine what exists in their environment and to acquire prey. Most snakes prey predominantly on rodents, although some will also eat bird eggs, nestlings, and insects. Snakes such as garter and gopher snakes and racers may occasionally be pests, but they are nonvenomous. Of the 32 species of snakes inhabiting Utah, the western rattlesnakes, the southwestern speckled rattlesnakes, the Mojave rattlesnakes, and the Mojave Desert sidewinders are the only venomous species. The western rattlesnake appears in most habitats throughout the state. The other three venomous species are in Washington County in southwestern Utah. There are four subspecies of the western rattlesnake, with the great basin rattlesnake being the most common. Rattlesnakes give birth in the autumn to hatches of 5 to 12 young, approximately 8 inches in length.
There are five ways to distinguish venomous from nonvenomous snakes. 1. There are rattles at the end of the tail, but the rattles may have broken off or the rattlesnake could be too young to have rattles yet. 2. Front fangs in addition to their rows of teeth. 3.Facial pits between the nostrils and eyes. 4.Broad, triangular head with the neck about half the width of the jaw. 5. Vertical and elliptical pupils may look like thin lines. Nonvenomous snakes have round pupils.
DAMAGE Snakes may take up residence under and possibly inside buildings. This behavior may become more noticeable in the fall when snakes begin seeking areas to hibernate for the winter. Nonvenomous snakes do not pose major problems for humans. A dead rattlesnake cannot strike, but the head, even decapitated, is still capable of biting and injecting poison. The snake's heat sensory pits are active until rigor-mortise sets in and they can trigger a biting response if a warm object, such as a hand, is placed near the snake's mouth.
If bitten by a rattlesnake remain as calm as possible because panic may actually trigger adverse physical reactions. Since there is a single antivenin available for use against all rattlesnakes in the United States there is no need to deliver the snake for identification prior to medical treatment. If it is a venomous snakebite, there may be one or two visible fang marks in addition to teeth marks. Evidence of a bite does not necessarily mean venom has been injected. The common and fairly quick reactions to envenomation are swelling and pain in the bite area, followed by a black and blue discoloration of the tissue and possibly nausea. If bitten get to a hospital as soon as possible. Remove items that may cause restrictions such as rings, shoes, and watches before swelling begins. Physicians do not recommend the use of a tourniquet, bite incisions, or suction. Antivenin may cause severe allergic reactions and it should be administered in a hospital where the patient can be closely monitored.
CONTROL METHODS Prevention Eliminate locations such as brush piles, growth adjacent to foundations, and high grass that provide shelter where snakes hide. Eliminating food sources such as insects and rodents will force snakes to seek food elsewhere. In areas with rattlesnake infestations consider building a snake proof fence around the yard or children’s play areas. All vegetation should be kept away from fences to discourage snake access. Prevent snakes from entering structures and crawl spaces by sealing openings with mortar or hardware cloth. Common entry sights include opening around doors, windows, and pipes. Be Prepared If walking or hiking in areas inhabited by rattlesnakes, wear long, loose pants, and calf high boots or snake guard materials. Rattlesnakes are generally non-aggressive toward humans unless they are stepped on, startled, or cornered. Rattlesnakes do not always rattle their tails before striking so do not rely solely on the sense of hearing. If confronted by a rattlesnake, try to remain calm and move away carefully.
LEGAL STATUS According to the Utah Division of Wildlife Resources, a person may not indiscriminately kill any reptile and they may not disturb the den of any reptile or kill, capture, or harass any reptile within 100 yards of a den without first obtaining a certificate of registration from the division. Rattlesnakes may be killed without a certificate of registration only for reasons of safety.
Source: VERTEBRATE PEST MANAGEMENT Study Guide for Pesticide Application and Safety P.30-31