This Bat House comes fully assembled. It is full sized, double celled and features an upper nursery which helps to prevent babies from falling out. Depending on the species, this Bat House will hold approximately 60 bats. It is wooden, lined with mesh and measures 18 inches high x 11.75 inches wide x 3.5 inches deep. Bats live in colonies and consume up to 500 insects per hour. It is best to place the bat house high with a minimum of 10 feet being the best. Adults and children will find this Bat House both entertaining and educational.