Bats tend to cause more fear than warranted. Less than .05 percent of bats are rabid, bats are not aggressive and will not attack people or pets. Nor do bats infest houses with dangerous parasites. Nevertheless, it is understandable if you do not want to share your home with these animals. Fortunately, removing bats from your crawl space or attic can usually be done without the aid of a professional and with little expense.
Wait until evening. Bats are nocturnal, and thus will be out feeding at night.
Check the outside of your home to determine how the bats are getting in and out. Possibilities include open windows, vents and loose siding.
Seal the entrance. Depending on how the bats are entering, this may involve using caulk, wire mesh or weather stripping. If you believe that there may still be bats inside the home, install a one-way bat door, available at most home and animal control stores, instead of sealing the hole. The one-way bat door will allow the bats to exit but not enter.
Repel the bats. If for some reason the bats are not leaving at night, you will need to force them outside. Naphthalene is a chemical that can be spread at a rate of 5 pounds per 2,000 cubic feet in your attic or crawl space. The substance emits an odor that repels bats and discourages them from returning for as long as the odor lasts. Note that while the chemical is safe for indoor use, people with respiratory problems should avoid the treated areas. Natural repellent alternatives include bright lights and electric fans.