This sign means you are entering the Bat House
These Giant Fruit Bats can be found along the Maharajah Jungle Trek in Disney's Animal Kingdom. These bats are huge and creepy and I don't really care how nice they are if I ever encountered one flying at me in the wild I would freak out.
I see these and all I can think of is this scene from Indiana Jones and the Temple of Doom. If you are bravery than I am stick around and an animal expert will tell you all about this creatures.
Here is a link to DisneyParks Blog on how they are special and not spooky.