Bats evoke extreme responses, from excitement to terror, especially if they invade your home. They are known carriers of rabies, so the good work they do eating insects is not a reason to harbor them in your attic or anywhere else in your house. If you have a bat infestation, blocking them from returning is the key to keeping the bats outdoors and ensuring that your home and family are safe from disease. The means of achieving this is an "exclusion trap," which is easy to install.
Things You'll Need
Wire mesh screen cut into one 12-by-12-inch section for each bat entry-exit hole
7 tack nails for each hole
Find the exit from your home where the bat or bats leave each evening to feed. You can do this by watching the exterior of your home around dusk. You will see the bats emerge from at least one opening. The opening can be as small as 3/8 inch in diameter.
Fold and bend a 12-by-12-inch square of wire mesh outward from the center of the bottom of the square. Widen as you go upward, making a rough funnel shape. Make sure the small end at the bottom of the funnel is no more than 2 inches wide.
Flatten the mesh against the surface it is being attached to so that it lies flush on all sides, except for the opening at the bottom of the funnel. You should now have a shape that is wider at the top and then tapers down, directing the bats out the hole in the bottom.
Tack the mesh over the opening from which the bats emerge. Use one tack nail at each corner, one in the middle of each side, and one at the top. Make sure the bottom of the funnel hugs the wall closely, only allowing an inch or two of space.
Watch for the bats to emerge toward evening and be sure you have covered all the exits with the mesh exclusion traps. If you have missed any, note the area and be sure to add a trap during the next daylight period. The traps that are in place will allow the bats to leave but not return.
Livetrapping bats is best left to professionals. Preventing the bats from returning to your home is a safe procedure if you are not handling the animals. Be sure to cover every possible entry or exit, as bats can use very tiny openings to gain entry.