Crocodiles are "cold-blooded". To get warm they lie in the sun. To cool down, they lie in the shade with their mouths wide open or laze in the water. To control their body temperature, crocs control the blood flow inside their bodies. They can 'shut down' blood flow or speed it up. We cannot do this!

A 3.5m crocodile has brain the same size as a walnut! However crocs have very good senses for finding prey and they learn quickly.

The long crocodile jaw is designed for grabbing prey. The jaw can open and shut but not move from side to side. Very powerful muscles snap the jaw closed when it grabs prey. The muscles that open the jaw are not as strong. Croc teeth are special too. Look at the diagram.

The croc's scaly skin is waterproof. For extra protection, the croc has bony scales and ridges along its back. The bumps along the tail are not bony. Instead they have lots of blood vessels which collect warmth from the sun.

To swim, the croc swings its powerful tail from side to side. Its legs are held against the body. Both feet have claws but the back feet are webbed. They can be used to swim backwards. Crocs can swim long distances and stay underwater for up to 5 hours. On land, crocodiles can move quickly although they also tire quickly. Crocs are sprinters, not long-distance runners!