Snakes reproduce sexually and usually mate in the spring or autumn. In warm, tropical countries, though, they mate all year round. Most snakes lay eggs. In mast cases, the female leaves the eggs once they are laid. As the young grow older, the leathery eggs grow bigger. The baby snakes hatch in around eight to ten weeks. They break out of their egg by slashing it with a special tooth that grows on their upper jaw. When the snakes have hatched, the tooth is shed.