UNIVERSITY PARK, Pa. -- Ask people what they'd do if they saw a snake in their yard and most will say, "Kill it!" But a wildlife biologist from Penn State's College of Agricultural Sciences has other ideas.

"People shouldn't kill snakes -- they're extremely good mousers," says Gary San Julian, professor of wildlife resources. "By reducing the rodent population, snakes reduce the potential for diseases such as hantavirus and Lyme disease. Rodents chew the insulation off of wire, causing short circuits and fires. Rodents also can do tremendous damage to agriculture, ruining billions of dollars of grain each year worldwide."

Pennsylvania has only three poisonous species of snake -- the timber rattlesnake, eastern massasauga rattlesnake and northern copperhead. The massasauga is found only in a few western counties.

"You can determine whether a snake is poisonous by looking at its eyes," San Julian says. "Nonpoisonous snakes in Pennsylvania have a circular pupil, while poisonous snakes have a vertically slitted pupil, like a cat."

If you don't want to get that close, San Julian suggests looking at the head. "Nonpoisonous snakes tend to have a round head," he says, "while poisonous snakes' heads are more triangular. The exception is water snakes, which -- although nonpoisonous in Pennsylvania -- can flatten their heads to a triangular shape when provoked."

If you still can't co-exist with snakes in your yard, San Julian has some suggestions. "You've probably watched the old movies where cowboys put a rope around their bedroll to keep snakes away," he says. "We've tested common folk preventatives, such as rope, moth balls, gourd vines, sulfur, artificial skunk scent and sticky materials, and the snakes passed freely through them. Your best bet is to make the environment inhospitable for snakes."

Snakes come into yards for a number of reasons, he says. "They like cover, so you may want to clean up old trash piles or messy woodpiles. You also should keep the grass around your house cut short. Snakes aren't likely to stay where the grass doesn't provide cover.

"You also should remove food sources for mice, because snakes come around looking for mice," he says. "Don't leave excess food out inside your house, and clean up the old food around bird feeders."

Homeowners should plug the holes in house foundations, and any places where utilities come through concrete walls. Animals such as snakes and mice may come inside out of curiosity; others are looking for food or a place to nest. You also should make sure screens are sealed.

If you find a snake in your basement, some experts suggest laying damp burlap bags in a corner or along a wall in the basement, then waiting for snakes to burrow under them and hide.

If you find a snake skin in your house, San Julian says you usually can assume the snake has gone. But if you want to be certain the snake wasn't poisonous, look under the tail. "Poisonous snakes have a single row of scales below the vent, while nonpoisonous snakes have two," he says.

"Any snake you see probably wants to get away from you more than you want to get away from it," San Julian says. "If you don't like snakes, it's easy to stay out of their way. I've spent more than 25 years tromping through the woods in seven states -- some that have more poisonous snakes than Pennsylvania -- and I've only seen three or four poisonous snakes. They're very elusive. You really have to be looking for them."

Although snakes hibernate in winter, you still can encounter them sunning themselves. "Even when it's close to freezing, the tops of rocks get quite warm on sunny days," he says.

"There are lots of myths about snakes," he says, "such as the story that a snake won't die until it hears thunder. People used to hang them on fences after killing them. Milk snakes were rumored to slide up to cows and suck milk from their teats. And hoop snakes were said to bite their tails and roll after you down hills. Most of these tales have no basis in fact, but they make great stories."

If you get bitten by a nonpoisonous snake, San Julian recommends washing the wound vigorously, putting on antiseptic and watching for infection. "Some people recommend you go to the doctor and make sure your tetanus shot is up to date," he says. "Because a snake's teeth grow down its throat, you may need to push the head forward to disengage the teeth. Snake teeth are very small. Getting a bite from a nonpoisonous snake is like being scratched by a briar, but the fear factor takes over in most people's minds."

Few people are bitten by poisonous snakes in Pennsylvania, and those who are usually were trying to capture or carelessly handle them. Snake bites are rarely fatal. According to the Pennsylvania Department of Health, no one died of a bite from a venomous snake or lizard in Pennsylvania from 1979 to 1997.

"A poisonous snake will make two puncture wounds surrounded by a series of smaller wounds," San Julian says. "If bitten, keep calm, move around as little as possible and get to the hospital," he says. "The old method of deep cutting and sucking out blood is more dangerous than the actual snakebite. If you can, identify or capture the snake, so the hospital will know what kind of antivenin to use."

Many people are so afraid of snakes they won't go into the woods, San Julian says. If you can calm them down and explain that a snake's not going to hurt them, you often can move them from looking at pictures, to seeing a live snake, to actually touching a snake. They usually won't go out and hug a snake, but they become much more at ease in the natural world.

"Even in the early biblical writings, snakes aren't the good guys," he adds. "But snakes are interesting, wonderful animals. Unless you step on them, pick them up or harass them, they're not going to hurt you. They just go on their way."

###

EDITORS: For more information, contact Gary San Julian at 814-863-0401.

Contacts: Kim Dionis KDionis@psu.edu 814-863-2703 814-865-1068 fax