*Japanese name: Abura komori *Scientific name:Pipistrellus abramus

* Description: Bats are mammals -- the only ones that can truly fly. They are furry and warm like mice, but their arms and fingers are extended. A thin membrane made of skin stretches between the fingers, along the side of their body and onto their feet to form the wing. They have very big ears. Adults are 4-6 cm long and live between four and five years.

* Where to find them: Pipistrelles live near humans. If you live in a very old house, you might have bats in the roof. They have even been known to live in air-conditioning units. They hibernate in winter to avoid the cold. You can see them now, even in Tokyo and big cities, flying around street lamps at night, hunting. They're smart, though -- they don't go out when it's raining.

* Food: Small insects that fly at night. A pipistrelle bat can eat up to 3,000 mosquito-size insects in one night -- a quarter of its body weight. Like all mammals, young bats drink milk from their mothers.

* Special features: Bats have a sixth sense: echolocation. You might hear them calling to each other in high-pitched squeaks, but they can make other squeaks so high-pitched that we can't hear them. The high-pitched squeaks bounce back off trees, walls and insects, and are picked up by the bat's ears. Just as a submarine can build a picture of its environment by listening to the reflections of its sonar, bats build a picture of their environment by listening to how their squeaks bounce back. When they detect a small, moving object, they increase the amount of squeaks to "focus" on the target, and home in on it with their mouths open.