tips for building bat houses - "chambers at least 14" wide and 24" tall (bigger is better), and a wide landing area with a very rough surface beneath the entrance. Do not use pressure treated lumber. These furry little creatures prefer temperatures between 85°F and 100°F."
Hope my sis and I can build this. I would love to attract bats to my neighbourhood. Bats do us a great service by eating a HUGE amount of flying insects (including MOSQUITOES) and consequently help to control some dangerous and harmful pests.