Description Entrance stones are specially designed to give building-dwelling bat species access to the cavity space. Depending on the underlying cavity space, entrance stones can be applied for summer, mating, maternity or winter roosting sites of common pipistrelle bats, soprano pipistrelle bats, late flyers such as the brown big-eared bats and mouse-eared bats. The entrance stone can be placed in the masonry in two ways: flush with the masonry, or slightly recessed, finished with stone strips. If insulation material is used in the underlying cavity space, this insulation material should be covered with grip mesh. This is to prevent bats from damaging the insulation material or getting entangled in the insulation material.
