Bats consume massive quantities of flying insects, especially mosquitoes, cucumber beetles, and codling moths. Provide a habitat for them and they will patrol for you. Ideally, a bat house should be located near water, in an unobstructed spot 12' to 15' high, facing east or southeast, so the house will warm up quickly in the morning. Bat houses are bottomless and have 1/8" black plastic mesh attached to the inside of the outer walls to which the bats cling. 11" wide x 3-1/2" deep x 17-1/4" tall, with room for 50 bats. Mounting brackets and complete information included. No maintenance required. A big brown bat can eat 3000-7000 mosquitoes every night. Try that with an electronic bug zapper!