After the rodents, bats are the second largest order of mammals. In fact, around one fifth of all mammal species are bats. They inhabit every continent except Antarctica (the presence of encircling seas not having deterred them from reaching Australia as it has most other placental groups), and all but the coldest of habitats. Unless you happen to live in, say, Iceland, there are probably bats of some sort living not too far away from you.And, yet, we don't know as much about them as we do most other broad types of mammal. They're mostly nocturnal, they fly about where it's difficult to spot them, and they tend to sleep in some pretty inaccessible places. That most people don't find them very cute and cuddly probably doesn't help much.
But, of course, they are pretty cool animals, when you think about it. The whole flight business is fairly remarkable, and has only been achieved on three other occasions in the entire evolutionary history of the animal kingdom. And, of course, there's the whole sonar business.
