Nigel Barley said this quote

“ Much has been written on the excellence of bats' navigation equipment. It is all false. Tropical bats spend their entire time flying into obstacles with a horrible thudding noise. They specialize in slamming into walls and falling, fluttering onto your face. As my own 'piece of equipment essential for the field' I would strongly recommend a tennis racket; it is devastatingly effective in clearing a room of bats. ”