Nothing would make herpetologist Charles Rau happier than to know that Cochise County residents aren't just out there randomly killing snakes, even rattlesnakes.

``When you live in an area like this, where there are a number of rattlesnakes, you have to be careful. They all have territories and they traverse those territories,'' he said at his home in Sierra Vista where snakes are a common sight around and in the house.

Rattlesnakes set up a specific home area that is generally around 500 to 600 square meters in size. They don't hibernate, but do slow way down in the colder months. They also have specific shelters in the home range that they travel between, he explained. In his back yard, he has seen a number of rattlesnakes, mostly the blacktail rattlesnakes that are common in the area.

``The best protection from a potential rattlesnake bite is education and knowledge. Educate yourself, your family and friends, and learn which snakes are harmless species and which are venomous and potentially dangerous,'' he says.

Most of the time, there will be little interaction between rattlesnakes and people. They tend to hunt during hours when most people are inactive.

And most snakes fear you as a potential threat and will not want to waste valuable venom on something they can't eat.

``If you see a rattlesnake, you should slowly back away at least 10 feet and stand motionless. The snake will probably move away from you. If it holds its ground, you back up more or just leave the area. It'll find a safe exit. It will not chase you,'' he said.

Getting rid of one in your yard can be just a matter of turning the garden hose on it. The negative encounter will more than likely leave a lasting impression on it, and it will not return.

Rau knows snake behavior, especially rattlesnake behavior. He spent 10 years in the Portal area researching behavior of the blacktail rattlesnake. As part of a team of researchers, he had many experiences in photographing and studying the reptiles up close and personal. Two males even did a courting battle at his feet. They were too busy to notice him, he said.

Trouble can be encountered when the snake has discovered a way to make mealtime quick and easy. If there is a mouse or rat problem around a home, a rattlesnake can decide to set up a ``blind'' to catch that little rodent. By detecting traces of rodent scent with flicks of its tongue, the snake can determine a good spot for hunting.

``People should not try to kill a snake themselves. They should call animal control or the fire department or call a snake expert. Let them handle it. Even a dead snake can envenomate by reflex bites hours after being killed,'' he said. ``Statistics show that 65 percent of the rattlesnakes bites that occur were due to the person provoking them in some way.''

Rau is one of those experts to call. He'll come and take care of the snake. He'll also train your dog to stay away from them in one trip to the home.

``It's important to me to teach the dog on its home ground. There's no distractions. When you put a dog in a strange place with other strange dogs, they tend not to pay full attention,'' he said. ``That's why I go to the home.''

Even bird-feeders, ponds and fountains can attract the pit vipers. Some, especially Western diamondbacks, eat birds, and when they catch the scent of those feathered creatures, they will want to visit _ frequently.

It can take a snake as long as a week or more to catch its choice of prey.

Of course, one would want the ``good'' snakes _ the kingsnakes and gopher snakes _ they eat the rodents, too. That's why he says it's important to know the different species.

While there are a number of products on the market that claim to deter snakes, Rau points out that none of them have evidence to support their effectiveness.

``It's important to remember that snakes are not aggressive by nature, but they will defend themselves if they are threatened. If you carelessly step on one, it will bite you. Any encounter with a rattlesnake has the potential to be dangerous,'' he said. ``Your knowledge and understanding about rattlesnakes and other reptiles can be invaluable to your family.''