Did you know that a single bat can eat 600 mosquitoes in a single evening? They also eat corn borers, cabbage moths and a number of other garden pests. You can encourage them to hang around your yard by setting up a bat house. It's as easy as climbing a ladder and placing one screw. Soon, up to 20 bats will call your neighborhood home. Site selection is important: They prefer to live 12-15' off the ground on a warm, south facing wall. So that's where I sent fearless Hannah! She put our's under the gable end of our garage roof, but we've yet to see a bat in there.