Gator Aids: Gators squish lungs around to dive and roll

Alligators turn out to have an unappreciated power organ for maneuvering underwater: their lungs.

AIR BAGS. An alligator contracts and expands muscles around its lungs to breathe (inset) and move underwater. When the large muscle contracts (inset, bottom), it pulls the liver toward the tail, helping the lungs inflate or shift position to tilt the body for diving.