Black rat snakes are hatched from eggs like most other snake species. Black rat snake reproduction begins in late April, May or early June, a few weeks after the adults snakes emerge from winter hibernation. The males use pheromones to attract females who travel through their territory.
After approximately five weeks the female lays between 12 and 20 eggs under hollow logs or leaves, or in an abandoned burrow. It takes 65 to 70 days for the eggs to hatch. Once the baby black rat snakes are born, they begin eating and double in size quickly. Under certain conditions female rat snakes can lay two clutches of eggs per year.