One of the most effective prevention measures is exclusion - performing structural maintenance to close potential entry points found during initial inspection. Treating for pest without considering prevention of the future issue is a waste of time. Repeated infestation must be prevented whenever possible.
Spring time is egg laying time for snakes. Eggs that are laid in the spring often hatch in the fall. Black snakes usually lay approximately 2 dozen oval shaped eggs in mulch and they often hatch in early October. Hatchling black snakes are 8 to 10 inches long and are light grey with dark blotches.
Fall is baby black snake time. Eggs that are laid in the spring often hatch in the fall. Warm Indian summer days bring them out and then as soon as it cools down they go straight into hibernation - typically right above the drop ceiling of home basements.