At different times of the year, I get questions about bats in structures. Bats are a timely issue towards the end of summer because young bats will soon be able to fly. Excluding bats from structures is limited to this time. This process is typically called “venting” where access points (both in use and potential) are identified, most are sealed off, and the remaining points are fitted with one-way doors that allow bats to leave but not reenter. If only the opening they use is sealed off, they will simply use another entry point. Think of it this way - our houses have multiple points of entry, but you may only use one. You will use another if necessary.
Bats can make their way into a house in a number of ways – gaps between siding and chimney, gaps between roof sheathing and fascia board, etc. New and old construction alike. Eliminating access to all of these small, potential points of access can be a challenge. The bodies of some bat species are as small as your thumb. Even though you don’t have an attic, there are still spaces inside a structure where bats can live.
Bats are one of the most difficult wildlife conflicts to deal with because of the nature of their habits. They can pass through extremely small openings, move throughout the inside of a structure, and often entre/occupy hard to reach areas. Bat exclusion is not an activity I recommend for most homeowners. There is a skill necessary to find and seal all possible access points. Since most of these are located high above ground and accessing these points can require special ladders, lifts and other safety equipment.
Having bats in the attic isn’t simply a nuisance issue, but also can be a safety issue. Like Most wildlife carry diseases. With bats, histoplasmosis and rabies are the two that are the ones most concern for people with bats in their homes. The Center of Disease Control (CDC) has good information on these and other diseases. Fleas that live on bats can also be vectors for disease. It is always a good idea to limit exposure to wildlife animals as much as possible. For bats, venting in the end of summer and fall and preventing reentry is a logical first step.
If you have bats and want to solve the problem now is the time to contact professionals who can help. Unfortunately, most nuisance wildlife control operators don’t do bat work because it requires specialized equipment and the difficulty of it. Because of that, control will not be cheap for the customer. Many people construct bat houses to attract bats. While beneficial, artificial bat houses will not attract bats from an attic.
Selecting a Nuisance Wildlife Control Professional, The Education Store-Purdue Extension's resource center
Bats in Indiana, Indiana Department of Natural Resources (IDNR)
Bat Houses, Bat Conservation International
Brian J. MacGowan, Extension Wildlife Specialist
Department of Forestry & Natural Resources, Purdue University