Bats can be a problem infestation in your home. They carry diseases that they can transmit to humans through bites and from their droppings [source: Illinois]. Some doctors feel that just seeing a bat in your house warrants receiving a rabies vaccination [source: Medline Plus]. Therefore, it's best to keep bats out of your home. Here are some tips about how you can keep bats out of your house:

  • Keep all your doors and windows shut, especially when it's dark out [source: University of Texas].
  • Make sure screens fit tightly to doors and windows, because bats can enter through holes as small as 3/8-inch (9.5-mm) in diameter. Also, plug any holes around the outside of your house with hardware cloth, aerosol foam insulation or weatherproofing strips.
  • Swap your outdoor light bulbs with yellow lights that attract less bugs, which are a primary source of food for bats.
  • Install stainless steel chimney caps with quarter-inch (6.35-mm) wire mesh to keep bats from entering furnace vents and chimneys [source: Ferraro, Hygnstrom, Vantassel].

If bats are already living in your home, you can take these steps to get rid of them:

  1. Identify bat entry points from stains caused by bat-body oils, urine and droppings. You can also watch after sunset for bats to leave your house in search of food to see where they come from [source: Glassy, Karlik].
  2. Create a one-way door by hanging quarter-inch (6.35 millimeter) netting over the entry points. When the bats fly into the netting, they fall to the ground where they can escape under the net and fly away. They won't be unable to figure out how to come back through the netting [source: Ferraro, Hygnstrom, Vantassel].