Why do some animals change gender during their lives?
Imagine you're a clownfish, bright orange and white, living in your sea anemone home. Right now you're a boy fish. But if something big changes in your reef — boom — your body can switch you into a girl fish. No surgery, no medicine. Just your own body, rewriting itself like flipping a light switch. Why would nature build animals this way?
Most animals are born one gender and stay that way forever. You're born, you grow up, you're done. But some animals play by different rules. They can change from male to female, or female to male, whenever their environment says "now's the time." It's called sequential hermaphroditism — a fancy term that just means "one gender, then the other, in order."
