Answer: Egg Temperature

If you’re a young alligator parent fretting over the sex of your babies, you don’t have to rely on the dubious tactics that human parents resort to—like calendar use, lunar cycle consultation, or diet alteration—you can simply keep your eggs warm or cold to determine the sex of your babies.

Unlike humans, alligators do not have a sex-defining chromosome that determines the sex of their offspring from conception. Instead, alligator fetuses produce hormones which alter their sex based on the temperature in which their eggs are incubated. If the incubation temperature is at or above 93 degrees Fahrenheit (34 degrees Celsius), then the alligator fetus releases hormones that turn it into a male alligator. Below that temperature and the hormones are not released, and the alligator remains female.

If sex determination somehow weighed heavily on the minds of a pair of alligator parents, then they could simply choose to lay their eggs in a shady nest or out in the sunlight to achieve their goal of a little brood of baby girls or boys.