Many people react to bats with revulsion, but you should think twice before discouraging bats from being on your property. These voracious feeders eat 600 to 1,000 insects per hour, helping rid your landscape of insect pests like gnats, flies, and mosquitoes. Bats do not harm people and contribute to local ecology.
If, however, you just can't tolerate bats living right outside your house, there are ways to discourage them. A place to start is by understanding their motivations. If bats congregate outside your home, it's very likely because you are providing them with an attractive dinner buffet or roosting area. Eliminating food and shelter causes bats to leave the vicinity to look for a more encouraging environment.
Here are a number of steps you can take to discourage bats from being present in your yard.
Eliminate Roosting Spots
Cut down and get rid of dead trees on your property, since they may be providing homes for bats. Move any piles of firewood to an enclosed woodshed or garage. Because dead wood plays host to so many insects, these areas are natural roosting spots for bats.
Look for Openings in Buildings
Look around your home and yard for evidence that bats are roosting in your garage, barn, or other outbuildings. Bat droppings are a major sign, as are oily, furry patches near roost entrances, called rub marks. If you listen carefully near openings in walls, you may hear the faint rustling or squeaking that is the hallmark of bat inhabitation. While you obviously want to block these entries into buildings, you also don't want to seal the bats inside.
To create one-way gates, nail or screw mesh screens over wide cracks and other openings, but leave the bottom free. This creates a one-way door that will allow bats to exit but make it impossible for them to get back in. A week or so will be enough time for all bats to exit. Then, you can permanently seal all holes and cracks with caulk. Cover larger holes with mesh screen or boards, and replace or seal any broken windows.
Remove Standing Water
If you want to discourage bats, remove standing water in your yard, whether it's a birdbath, small pond, or an empty container that traps rainwater. If you want to keep the water feature but don't want bats, place netting over the water so the bats cannot access it. This can be a good option for fish ponds.
Control insects around your yard with moth lights, fly strips, citronella candles, or other methods. Consider removing plants that bloom at night from your garden, as well, cause night-blooming plants attract insects at the precise time that bats are feeding. The fewer insects that are present, the less attractive your yard will be to bats.
Eliminate Ground Debris
Rake up leaves frequently in the fall. Some tree-dwelling bats spend their winter hibernation tucked away under piles of leaves left on the ground. Keeping your lawn and garden tidy eliminates this potential hibernation site.