2. There’s a strange scracthing sound coming from behind the walls
The problem: If you hear strange noises such as scratching and possibly chittering coming from places where no one lives in the house, you could have mice, squirrels, raccoons or even bats sharing your quarters, Richardson says.
“Any kind of wild critter could be up in the attic,” he says. And these freeloaders aren’t just a nuisance: Bats can carry deadly rabies. In the Southwest, the droppings of mice can spread hantavirus. Some animals will tear up insulation to nest, or chew through siding or even electrical wires, causing fires.
The solution: As soon as you suspect an intruder, get on it: Set traps. Call in a pro if the animal is stubborn or large. Finally, prevent the problem from reoccurring by sealing up the entrances to your house with steel wool, metal sheeting, caulk, hardware cloth or all of the above.
To keep raccoons away, put garbage in sealed, secured metal cans that can’t be tipped. Bring pet food inside. After pests have been removed, make sure vents and chimneys are securely covered with mesh or a grill, so those spaces can still breathe.