Why do worms come out of animals' butts?

Question

Is it because they are crowded, having fun, or some logical reason?

Answer 1

Because many parasitic worm species lay their eggs in the grass, which many animals each. They hatch in the animals' digestive system and a worm grows in there and eats much of the food being digested by the animal. Occasionally, the worm gets crapped out of the animal, either to reproduce or because of something in the animal's digestive system

Answer 2

It's easier than chewing a hole in their stomach.

Answer 3

because the digestive system is where they live.

Answer 4

If you were up an animal's butt, would you want to stay there?