Bats are mammals and therefore exhibit the common characteristics of all mammals (with only a few exceptions as noted):

- body hair or fur
- mammary glands (feed babies milk)
- two sets of teeth
- warm-blooded
- live birth (placental - exceptions include platypus/echidna/marsupials)
- breathe air
- limbs

There are other ‘peculiarities’ of mammals not typically considered, but mammals also exhibit a single bone constituting the lower jaw, as opposed to the complex of bones found in the lower jaws of other terrestrial vertebrates.

Three ear bones in the middle ear region is another characteristic of mammals.

The Wing
The Ears
The Eyes
The Hindlimb and Foot
The Circulatory System