Big Brown Bat, Eptesicus fuscus, big brown bats, bat, bats, nocturnal, night animal, vespertilionid, vespertilionids, vesper, insectivore, insectivores, insectivorous, night flying, night flight, carnivore, carnivorous, carnivores, pest control, insect eating, beneficial, brown, fur, mammal, mammals, biosonar, face, face closeup, face close-up, teeth, fang, fangs, open mouth, mouth, aggression, aggressive