Opossums are marsupial omnivores that are common in many areas. Also known as possums, these slow-moving, ratlike creatures often scavenge garbage cans and dumpsters for food and, for the most part, are harmless. When a possum takes up residence in an attic, however, removing it is essential to avoid damage to the home. A possum may decide to move into an attic for several reasons: It's a warm place, it provides shelter and it even provides a food source in some cases. Trapping and relocating a possum can lead to the animal's death, due to the fact that it cannot find food or shelter in unfamiliar territory. Instead, use a method to discourage the possum out of an attic.
Remove food attractants from around the affected house. This includes low-to-the-ground bird feeders and pet food bowls that are outdoors.
Clip one or two high-wattage clip-on lights in the attic. Bright lights discourage possums and most pest mammals.
Soak rags in ammonia, and scatter them in the attic. Although this will give the attic a noxious odor for some time, it will discourage the possum from nesting in the attic.
Set up a radio in the attic, and use it to play loud music 24 hours per day. Loud sounds will make the attic an undesirable habitat for a possum.
Nail hardware mesh over all cracks and spaces after the possum leaves the attic. The mesh will keep the possum from getting back in the attic and force it to find shelter elsewhere. It is very important that the possum leaves the attic before you seal cracks and spaces.