Most of us think that snakes lay eggs. But this is only true of the part. According to National Geographic, only 70% of snakes in the world lay eggs. Oviparous snakes tend to live in a warmer climate, which helps during the incubation period. The remaining 30% are viviparous.
The main difference between egg-living animals and placental viviparous animals is that in the first case the embryo feeds mainly on the substances contained in the egg yolk and is separated from the metabolism in the mother’s body. In viviparous animals, the fetus is fed directly from the mother’s body.
Eggs are alive all boas, many vipers, aspidum. At the same time, real live birth is typical of the American garter, the Russian common viper and many sea snakes. These species live near water bodies or in damp lowlands. However, there are viviparous snakes and far away from water bodies.
Snakes, who managed to master live birth, have a lot of advantages. First of all, their eggs are constantly under reliable protection. In this case, the mother can quietly hunt, and not sit at the nest. In addition, the snake can choose at any time the most suitable places – well warmed up, which is especially important in the north, or cool, which is very important in tropical deserts.