Unless it's a pet, nobody wants a rodent in the house. Rats can carry a dozen diseases and they contaminate about 10 times as much food as they eat. Mice may look cuter, but they carry many of the same pathogens as rats and one pair of mice can produce up to 87 children in a year.

So what if wily critters take residence in your attic, basement or walls?

"While there are approved poisons for mouse or rat control, part of the problem with using them is the rodent dying within your wall or attic and starting to smell," said Greg Clark, Napa County's assistant agricultural commissioner. "Also, there is the chance of secondary poisoning. A non-targeted organism, another animal, may eat the poisoned rodent."

That's why most professional exterminators don't recommend poison, according to the nonprofit Washington Toxics Coalition. If the home occupant wants to tackle the problem without the assistance of a professional, the organization recommends using a trap. There are many available, including the old-fashioned snap trap. There are also newer traps that are easier to set and have the advantage of allowing the trapper to release the rodent without touching it.

Washington Toxics Coalition suggests placing traps where rodents pass. Good spots are along walls, especially near a known entry hole. When setting traps along the wall, position them with the triggers toward the wall because the animals tend to run close to the wall. If the traps are in the open and you have small children or pets, protect them from the traps by covering the traps with a box or board taped to the wall or floor.

Because your scent may scare rodents, never handle the traps with your bare hands. For bait, experts suggest peanut butter because its stickiness makes it more likely for the animal to set off the trap.

What to do if you catch a rodent?

"There is no local regulation or requirement for disposing of the animal," said Clark. "We recommend putting your hand inside a plastic grocery bag, take hold of the animal and pull the bag over it, so you don't have to touch it. It may be thrown into a securely fastened trash can."

Clark recommends rodent prevention.

"Rats and mice simply want shelter, a protected space, food and water. Put steel wool or hardware cloth over entrances to water pipes and where roof lines overlap."

Rats can enter a hole larger than one-half inch square and mice can pass through a one-quarter inch opening.

"The best method of control is exclusion," said Clark. "Don't leave pet food outside. Remove vegetation and prune tree limbs so they don't touch the house."

Washington Toxics Coalition adds to remove fruits, vegetables and bird seeds from the ground, do not pile wood next to your home, remove animal droppings and trash from your property and close every possible entry to your home, including windows, doors, vents, pet doors and small gaps under the eaves.

If all else fails, hire a competent professional who can set traps and advise on needed repairs.