Now think hard before you read the answer. What can bats do that no other mammal can?
This is a brand new sign with the following features:
12" x 12" screen printed on caution yellow
Sturdy .032 aluminum sign with rounded corners and drilled hole for hanging
Here's the answer. Bats can truly fly. Their forelimbs have developed into wings. In fact the family name, Chirotetera, means "hand wing". This sign features a picture of bats in flight.