<^Animal Hearing> Most mammals have ears that work the same way <#5682,10><!human ears> do. But many of them can hear and respond to sounds of far higher or lower frequencies than human ears can hear. Bats have very poor vision, but they are able to find their way around by responding to the reflected sound <#5675,6><!waves> of their own high-pitched squeaks. Elephants can hear, and even communicate with, sounds so low that humans can’t hear them at all.
Insects have very different ears from humans. Most insects can’t even hear very well - their ears are just simple membranes that vibrate when sound waves push against them. Some insects are able to “hear” in other ways. Cockroaches, for example, have vibration detectors in their legs that are sensitive enough to detect even the footfall of another cockroach!
Many fish have internal air bladders that pick up sound vibrations in the water and relay them to the fish’s inner ear.
Amphibians, such as the frog, have an exposed disk behind their eyes that acts like a mammal’s eardrum.
Although most reptiles have eardrums, snakes, curiously enough, do not. They are only able to hear because <#5675,6><!sound waves> are transmitted to their inner ear by vibrations in the bones of the snake’s skull!
