These two huge Logger Head turtles face off (almost literally) when they become too close to each other.
The 29 pound turtle to the left clinches down on the slightly smaller turtle to the right and bites down hard.
The larger turtles bite is actually started to break the skull and penetrate into the skull of the smaller one.
We could hear the skull cracking!

This is called the Death Grip! If he grabs and bites you, he probably won't let go!