Although not every species of snakes is known to lay eggs, about 70% of snakes do, while the rest give live birth. Snakes that give birth to their young without laying eggs are called viviparous. These snakes live in colder climates where eggs would not incubate as well.
Whereas snakes that do lay eggs fall into two categories: oviparous and ovoviviparous. The eggs a snake lays has a hard shell that protects it and they are usually found places under leaf litter or loose soil, or sometimes even within a burrow or hollow stump.
Oviparous snakes lay eggs that hatch outside of the mother after they develop. In most cases the embryos develop mainly outside of the mother but are usually not placed outside of the snake’s body until the mother travels a great distance to find a good hiding place for its eggs. Sometimes these snakes will even share space with the eggs of many other females, and when they are ready to hatch the young snakes poke their way out of the eggs much like a baby bird. Some snakes are very protective of their eggs where others are not as defensive. It depends on the species. Pythons are known to coil themselves around the eggs to keep them warm and help them hatch by gently squeezing her body. After young snakes or born or hatched, their parents do not take care of them, they are left to fend for themselves.
Ovoviviparous snakes hold their eggs inside of their stomachs until the eggs are ready to hatch. This helps protect them fully from predators. It is harder or a mother to swallow food or protect herself during this process however. This is probably why all egg laying snakes have not evolved to be ovoviviparous.
Generally for the most part, a female snake lays her eggs after she mates with a male snake. One exception to this rule is the flowerpot snake which are all female and can reproduce without a male snake. Female snakes are equipped with a vent which leads to her cloaca, which is the area that semen and eggs are passed through. The amount of time that it takes for an egg to hatch, for egg laying snakes varies greatly depending on the breed.
The number of eggs that a snake lays can vary as well. Some snakes have been known to lay as many as 100 eggs at a time. Baby snakes typically stay in their eggs for two to three months or sometimes shorter in breeds that remain inside of ther mother’s body for a period of time. These snakes then break out using a special “egg tooth” Although snakes are known to hatch from their eggs much in the same way as birds do, their eggs differ in that a snake’s egg is soft and leathery instead of hard and rigid.
Three pit vipers such as the copperhead, cottonmouth, and rattlesnake give birth to live babies that are on their own immediately after birth and born with fangs and venom to help defend themselves against predators. Whereas snakes such as the texas coral lays three to four eggs in the spring and then hatch in June-September.