First of all, because snakes are cold-blooded, they don't need to kill their prey all the time to maintain their heat. Many snakes survived after extinction, which gave them a basis for development after extinction. In fact, on the surface, the prehistoric extinction did cause the death of many animals, but most of those dead animals were huge warm-blooded animals, which kept moving on the surface and needed to eat constantly to maintain their own heat. As a cold-blooded animal, snakes can be said to be full for ten or twenty days, and then they can hide in the corner to recuperate. It is precisely because many snakes have increased that they have avoided the fate of extinction and can continue to survive and develop after the prehistoric extinction.

Secondly, the prehistoric extinction made many natural enemies of snakes extinct. Without the threat of natural enemies, snakes will naturally increase. Before the prehistoric extinction, the ecological environment of the earth was in a relatively balanced state, and the snake population was also controlled by various natural enemies. After the prehistoric extinction, the ecological balance of the earth has changed greatly, and the species and number of natural enemies of snakes have also decreased greatly. This makes the development of snakes can not be effectively controlled, and the number is increasing, gradually becoming the overlord.

Finally, the prehistoric extinction caused the extinction of many predators, and the development of many small animals ushered in spring, enriching the food sources of snakes. In fact, there is no prerequisite for snakes to flourish, that is, there is enough food, and prehistoric extinction has indeed made snakes have a lot more food. Because many large predators died during the prehistoric extinction, many small animals were much less likely to be killed by large predators, and the number naturally increased. Moreover, many snakes feed on small animals and naturally don't worry about food.