Do chickens have periods?

Answer

Dear Emma,

To start menstruating you need a uterus, a chicken doesn’t have that. Actually, animals other than humans and similar (eg chimpanzees) do not have periods. This is because the cycle in those animals is hormonally regulated differently and the mucous membrane of the uterus (which peels off in humans during menstruation) disappears spontaneously in most animals.

Chickens therefore do not have a menstrual period, but they do ovulate (ovulation) and this almost daily. During ovulation, a blood vessel can sometimes break and you will see a small red dot in the egg.

Herman Finkers once said “all animals have a monthly cycle, except the mollusks”, but as you now know this is not correct.

kind regards,