Strange Science: Why Do Male Cats Have Nipples?

Did you know that male cats have nipples? Did you ever wonder why?

The reason for this is that when kittens are first embryos, they start out without any characteristics that will determine their biological sex. And nipples are part of that standard kitten embryo package. Interestingly enough, this is true of MOST mammals, including humans (so you’ve got a bonus explanation as to why humans of any gender have nipples). And as one writer explains, “Because it doesn’t hurt males to have nipples, most mammals haven’t evolved away from them.”

To learn more about extraneous nipples in mammals, you can check out this Q&A on cats or this article on humans!