Bat guano (droppings) and urine can cause a foul smell, as well as the lung infection histoplasmosis, which is caused by inhaling the spores of a fungus carried in guano. Urine and guano can also attract other pests, such as cockroaches, corrode wood and drywall, and grow mold.
Colonies usually consist of at least 40 mother bats and their babies. If bats have invaded your home, it is best to seek the help of a professional to remove them. Repellant products and devices do not work. The only effective, legal, and humane way to remove bats is through a live exclusion, using devices such as netting, screening, funnels, or cones that allow the bats to fly out but prevent them from returning.
It is important to know the species of bat you have in your home, since that will tell you when their maternity season is. Bats cannot be excluded during maternity season since the flightless babies will be left inside to starve. Their mothers will look for other ways into the house, including open windows and doors. The babies can also crawl down into the walls and die.
After the bats have been removed, you must have the entry points sealed to keep them from coming back. Bats can squeeze through spaces as small as 3/8 of an inch wide in the roof, vents, gables, ridge caps, gaps in siding, missing bricks, or broken windows. Entry points can be sealed with plastic or metal screening, caulk, or high-density polyurethane. The guano and urine in your attic then need to be cleaned.
If you have a problem with bats in your attic, call Anderson Wildlife Control, a team of experienced professionals who can remove the bats from your home once and for all.