[ELI5] How do animals know not to inbreed?

Question

[ELI5] How do animals know not to inbreed?

In: Biology

Answer 1

They don’t. Ask anyone who has had gerbils. They screw their siblings and cousins and breed until you have a house full of one-eyed, 3 legged little mother f***.

I. Am. Not. Even. Kidding.