Bats in Attic

June 29th 2007
Bats in Attic

Q: We have had problems with bats in our attic ever since two barns were torn down near our home. We have been told by a pest control company that they can't be removed until the fall. Any suggestions?

A: Bat proofing a structure is the best way to manage a bat infestation permanently but only at certain times can exclusion be performed if bats are roosting in the attic. Bat entry points are best sealed during the months of September through April, when no bats are present. This involves sealing openings after the young bats are old enough to fly (mid August or later). Bats may leave in September and October to migrate. Sealing will prevent bats from entering the structure in spring.

Seal all points of entry such as openings larger than a half-inch; under eaves, gaps around utility lines and holes around chimneys and windows. Also, ensure doors, windows and vents have screens and are securely framed and chimneys are capped. Larger opening can be sealed with high quality caulk, 1/4-inch wire lath, sheets of metal or window screens. Bright lights, fans and ultrasonic devices may be effective but are only temporary controls.

Use of light: Since bats tend to avoid daylight, illuminating an attic may cause them to leave for another location. This method is more effective if done shortly after bats return from hibernating sites.

Bat Houses
Bats are important insect predators so putting up a bat house will give them a new place to roost in a structure other than where people are living. Install a bat house in a tree or post where they will not represent a nuisance and you will also keep them in the neighborhood eating your bugs; up to 600 to 1000 bugs an hour. Bat houses can be purchased at hardware stores or easily built.

For more information on Bat Houses and bat control in your home check out