Central bearded dragons can grow to about 2 feet long. Half of the length of a bearded dragon's body is its tail. Females are usually smaller than males. If a bearded dragon is scared, it will flatten its body against the ground, puff out its spiky throat, and open its jaws to make itself look larger. Bearded dragons sometimes open their mouths wide to allow hot air to warm them better when they are lying in the sun. They also open their mouths to help them cool down; the warm air and heat escapes through their mouths. This behavior is similar to panting.