Excluding Bats - Helpful Tips


There are forty different species of bats found in the USA. The big brown rat, little brown bat, and Mexican free-tailed bat are common bats in the United States. Bats rarely attack people and can be beneficial as they feed on insects. However, bats may become a pest if they set up residence within your building with their droppings, urine and squeaking sounds.

There are no chemical solutions or pest control products that we have found that get rid of bats. The best bat control is to exclude them from your structures. We have included a link below that has plans to get rid of bat colonies.

Behavior and Biology

Most of the time bats root in natural shelters like drainage pipes, hollow trees, and caves, but can roost and breed within occupied buildings during warm weather.

During the first warm days of spring, most bats leave their overwintering/hibernating sites and enter structures. Most of these bats are females preparing to birth in June and July.

  1. Inspection
    • Inspect possible exit and entry points that the bats are using and any structural defects that the bats are using for entry. Common entry areas include louvers, rooflines (between the roof sheathing and the fascia boards). Openings of 3/8 inch or larger are sufficient for bat entry. Droppings on the ground, smudge marks, odor, noise can also give you a clue to their entry/exit points.
    • Inspect twice, at first dusk when the bats are first emerging and the second one during the daytime to find roosting areas. Unless it is unseasonably cold or rainy, bats will emerge each evening.
    • Inspect the roofline right before dusk. It may be necessary to position two or more people at different angles of the structure to view multiple rooflines at a time when the bats are emerging. This will reveal entry and exit points.
  2. Excluding Bats in Buildings

Bats and Rabies: Only a small percentage of bats carry rabies, but proper clothes (coveralls, hard hat and heavy leather gloves) should be worn during any bat control procedures.

We are having a problem with bats flying around our living room window and in the alcove at the front door. Our pest control company has no answers for us except for a spray that will discolor the paint on our house. At present we are using the sticky strips used for catching mice. We tacked two of them in the alcove area. After a month, we caught nine. Do you have a suggestion for us on how to discourage these flying pests from using our front porch? They leave their droppings everywhere.

A yellow bug light might attract fewer insects, a major attractant for bats. This may cause the bats to find food elsewhere. If they are nesting in the eaves, you can screen the entry points at night after the bats are gone.

We seem to have a colony of bats (at least 60-75). They have made their home in the exterior wall of our garage. How do we get rid of them? Will they stay forever or will they go away?

You need to fashion a one-way door, so the bats can come out but not come back inside. Another thing you can do is to seal the entry points at night while the bats are out. I would advise you to do this in the spring. They are nesting with the young in the fall. Many babies and females may be inside at night. Also if you provide bat houses for them in the area, they will stay around to kill all your other flying insects. Allow the bat house a couple of years to start really working. Bats are great for mosquito control !

We just bought an old house, and we had to go into the attic to clean about 7 bags of bat droppings, we are starting to see them, and we really want to get rid of them. What works? We've been told moth balls work great. Is that true?

If you put enough mothballs to do the job, it would probably run you out of the house. I would suggest you seal the openings where the bats enter and exit. See Exclusion Guidelines from Bat Conservation International.