Midsize pests include squirrels, groundhogs, skunks, porcupines, raccoons, and opossums, depending on your area, and can be a problem in both rural and urban areas. You're most likely to find them seeking shelter in attics, crawlspaces, decks, porches, and stairways. While they look cute, animals such as skunks and raccoons in particular can carry rabies, and any animal that's nesting in or close to the house brings insects and fecal matter with it.

The best option for getting rid of them is to call an exterminator, preferably one that has humane options for removal. You don't want to trap adult animals in the spring, for example, because you may be leaving babies inside the house-starvation is particularly inhumane.

If you're sure that there are no baby animals involved, watch for the animals leaving or entering the house. Once you've identified the access point, install a one-way door over it, or seal it up after the animal has left. If the animal is reluctant to leave, try using commercial repellents or rags soaked in ammonia close to the entryway. Bright lights, cayenne pepper, and radios playing all night also make your house less hospitable. Squirrels and skunks aren't fond of mothballs, either.

For burrowing animals like woodchucks and skunks, shield crawlspaces and areas below porches and decks. Fill any spaces that could become dens with dirt, and bury wire mesh fences at least 8 to 12 inches into the ground.