A Saltwater Crocodile sunbakes with its mouth wide open. This behaviour is not territorial or to scare off competition, it is a way these crocodiles thermoregulate. Being cold blooded the activity and efficiency of crocodile locomotion correlates to their body temperature. After hunting saltwater crocodiles will pull themselves onto the bank and into the sun allowing themselves to warm up. This accelerates digestion. They open their mouth to allow the rest of their body to continue to heat up while ensuring their brain doesn't overheat.