Bats!

In honor of Halloween, allow me to present facts about bats from the Smithsonian Institute:

1.  There are 900 species of bats.  OK, how hard can it be to be a bat? You fly, eat and sleep hanging upside down. Apparently 900 different ways.

2.  Bats are the only mammal that can actually fly.  Flying squirrels can only glide.  Sorry, Rocket J.

3.  Young bats sometimes fall from the roosting area.  Ow.
4.  Bats give birth while hanging head down.  So the female has to defy gravity along with all the other discomforts of having a baby bat.  When the babies grow up do they ever call?  No.  She's only their mother.

More bat facts from the Encyclopedia Smithsonian