Mounting a bat house on your property is the perfect way to help bats who are in need of a safe place to live while protecting your yard from pesky night-flying insects. Size 15.4 x 4.4 x 20 inches . Made of fir wood, notched inside for easy grip. Hang the bat house at least 10' off the ground in a south or east facing direction. Do not hang from a tree, as this area will be too cold and shady. Place near a water source and away from bright lights for optimum results. Mount the house on a garage, barn or pole (south or east facing is usually best). Do not mount on a tree as it enables predators, is usually too shady (cold), and the branches impede the bats' flight. Place the house a minimum of 10'H off the ground to protect against predators; 15-20'H is best. You'll have a better chance of attracting bats if the house is near a water source, and away from bright lights.