Only the females ever go ashore and then only to lay eggs. Terrapins and many other turtles hibernate each winter. When the first cold weather arrives, they bury themselves in mud banks. Their body functions slow down greatly, and they do not need to come up to breathe. If there is a break in the cold weather, the terrapins may come out to take advantage of the warmth.
Hibernation ends in the spring, and mating takes place soon afterwards.
Breeding Terrapins reproduce when the males are 6 to 10 years old and the females are between 8 and 13. Diamondbacks always mate in the water, usually at night. After laying her eggs, the female terrapin will not mate again for up to four years. Terrapins nest April to May in the southern regions, later further north. Incubation takes 9 to 15 weeks.