Observation Bat House The Observation Bat House's Plexiglas window allows you to observe the bats within the house. Verifying usage of the box and health of the colony has never been easier. This two chambered house is large enough to shelter up to 100 bats. Bats are heat-seekers. In Canada, the exterior of the house should be painted or tinted in black, and facing south. Screening on the landing surface and within the shelter itself is like a "bat red carpet." Children and grown-ups alike will be mesmerized by the inside view.