A rat infestation can cause serious damage to your home, as well as a health risk to your family. There are measures you can take to reduce the risk of inviting rodents into your home and limit their effect if they do get inside.
There are two major types of rat in the United States. The Norway rat is a large, stocky rodent with a grayish belly, blunt muzzle, short ears and a tail that is shorter than its body. It usually lives in the basement or ground floor. The roof rat, also known as the black rat, is a smaller, sleeker animal with a gray to white belly. Its tail is longer than its body, it has a pointed muzzle, and its ears are longer than those of the Norway rat. It usually nests in attics, walls, cabinets and other elevated or enclosed spaces.
Sanitation is essential to eliminating a rat infestation. Remove garbage and debris regularly and keep garbage in containers with tight-fitting lids. Feed your pets only what they will eat in one meal and store pet food in rodent-proof containers. You can also take steps to rodent-proof your home. Build a tight-fitting cover for the crawl space under the house; seal all openings around pipes, cables, and wires that enter the house through a wall or the foundation. Keep your window screens in good repair and install screens over your dryer vents. Cover rooftop plumbing vents with screens if they are more than 2 inches in diameter.
If you have found evidence of rats inside your house, the best method of control is trapping. Rat bait is not recommended, as a baited rat may get inside a wall and die, causing a foul stench. You also risk your pet or a child getting into the bait with tragic consequences. Bait your rat traps with nuts or dried fruit and fasten the bait securely to the trigger with thread or fine wire. Do not use soft baits like peanut butter, as the rats can take it without triggering the trap. You can make it easier to catch rats by leaving the trap unset long enough for the bait to be taken once or twice; this gets the rats accustomed to the trap and increases the likelihood of catching them when you do set it.
Trap locations will depend on the type of rat you are having trouble with. To catch Norway rats, set the traps close and at right angles to walls, with the trigger end nearly touching the wall. Other good places to trap Norway rats are behind objects, in dark corners and anywhere you've seen droppings or other signs of the rats' presence.
To catch roof rats, set traps in off-ground locations; if possible, set them along the routes between the rats' nests and food source. Ledges, shelves and pipes are good locations for trapping roof rats. You may need to fasten the traps down with screws or wire in some of these areas.