It’s because of evolution that snakes no longer have legs, there are also species of snakes that give birth to live young as well as laying eggs. In fact, 70% of snake are oviparous. This means that they lay eggs which need warm temperatures to hatch. Snakes that are oviparous are cobras, mambas and adders among many others.
However, 30% of snakes give birth to live young. This 30% of snakes include both viviparous and ovoviviparous snakes. Viviparous snakes give birth to live young and no egg is included in the reproduction of the snakes. Ovoviviparous includes eggs, but the female snakes still give birth to live young. Snakes such as boa constrictors and green anacondas, while rattlesnakes, for example, are ovoviviparous snakes.