Black spots and short squiggley lines create a design that is unique for each animal. Diamondbacks also have webbed feet, which make them able swimmers. Female terrapins are much larger than the males, more so than any other North American turtle. Nesting and Hibernation Terrapins reproduce when the males are 6-10 years old and the females are between 8 and 13. In Maryland, nesting takes place in June and July.
Diamondbacks always mate in the water, usually at night.
A female lays fertilized eggs for up to four years before mating again. Nests are located above the hide tide mark, on river banks or the sandy edges of salt marshes. A female may make three or four nests. The eggs take 60-100 days to hatch. With most turtles, the temperature of the nest determines th e sex of the hatchlings.