Roosters cannot lay eggs because they are male chickens and lack the reproductive anatomy necessary for egg production.

Egg-laying is a function of the female reproductive system in birds, specifically hens (female chickens). The hen has an ovary containing ova (egg cells), which develop into yolks. These yolks then travel down the oviduct, where they are fertilized (if a rooster has mated with the hen), encapsulated with albumen (egg white), and finally encased in a shell inside the hen’s uterus before being laid as an egg.

Roosters, on the other hand, possess testes that produce sperm. Their primary role in reproduction is to fertilize the eggs through mating, but they do not have the organs required for egg formation or laying. So, the inability of roosters to lay eggs is due to fundamental differences in their reproductive biology compared to hens.