Why do reptiles differ in their care of the young?

Some reptiles are good parents, others are not. Some lay their eggs under rocks and logs, while others carefully build nests. Turtles deposit their eggs in nests that are usually holes dug in the sand. The American alligator lays her eggs in a cavity that she creates within a pile of material. She closes the cavity by lying down on top of the eggs. The female king Cobra makes a nest from plant materials. She gathers leaves, bamboo stalks and sand into a pile, using the coils of her body. She then makes a chamber in the middle of this pile and lays her eggs in it.

Turtles don’t take much care of their eggs, but the American alligator is a good parent. The female guards her eggs, and defends the clutch from predators. Some species of pythons coil around their eggs protectively and incubate them by raising the temperature of their bodies. The Nile crocodile carries her eggs to the water when they are about to hatch, rolling each egg against the roof of her mouth to crack the shell. The little crocodile is then released in the water, and the mother remains nearby to see that it comes to no harm.