Dark, warm places like the insides of ceilings make ideal homes and hideouts for bats. Though bats are not vicious and will generally not attack humans, bats in your ceiling can create odors, their urine and feces can cause structural damage and the animals may carry rabies. Therefore, it is important to get rid of bats if you find them living in your ceiling. Fortunately, there are many ways to get rid of bats without killing them.
Visually inspect your house for exiting bats. At dusk, stand outside of your home and make note of where bats are exiting. This will let you know how they are getting in—information you will use to keep your house bat free.
Drive the remaining bats out with bright lights. Bats do not like bright lights and like to hide in places like ceilings, in part because they are dark. Shine bright lights into the ceiling space to agitate the bats and encourage them to find a darker place.
Lay down fiberglass insulation in the ceiling to make the space uncomfortable for bats. Fiberglass is painful to bats, so if they do come back, they will not stay.
Seal off the bats' entrances. Check for cracks in your roof that might be entrances for bats. Common entrance spots are the edges under eaves, loose fitting shingles and openings near vents. Use caulk or wood patches to close these openings so bats do not get back in.
Call an exterminator or animal control specialist for an inspection. Bats may have left behind droppings and remnants of their nests, or there may be younger, weaker or more stubborn bats left behind. A professional will be able to clean up after the bats and make sure that no other animals remain.