Urine from bats. The biggest issue with bat urine is not one of human health, but rather one of high quantities of uric acid, which may corrode metal. Bat urine may also erode polished surfaces and stain light-colored materials and porous stones like marble and alabaster. There are several species of bats that can be found in the United States. They include: silver-haired, big brown, and tricolored bats. Each species has different dietary requirements so not all bat urine is created equal. Bats have poor vision and rely on other senses to find food and avoid danger. Their primary sense is smell, used for locating food sources and recognizing friends and enemies. Hearing plays a role in finding mates and calling babies back to their colonies. Bats also use their wings to feel their way around when they can't see what's ahead. Although they can fly fairly well for animals their size, they usually follow roads and buildings until they come to a place where they can go underground or into caves or mines. Bats' large ears act as antennas to help them hear insects near their mouths. The sound waves travel through the head into the ear opening, where they are amplified by the cartilage and then into the inner ear. This allows bats to listen to sounds that we cannot hear, such as those made by flying insects. The first veterinary report of a disease associated with bats was written in 1917.