By size mostly. That depends on what type of terrapin you are referring to, of course.
if a terrapin is 9 months old how can you tell if its a boy or girl
boy terrapin has spots and woman terrapin smell betterAnd The Guy Terrapins Have Longer Claws
You can estimate a terrapin's age by examining its size, weight, and shell condition. Younger terrapins tend to be smaller and lighter with smoother shells, while older terrapins are larger and heavier with more worn shells. Additionally, counting growth rings on a terrapin's scutes or vertebrae can provide a rough estimate of its age.
Turtle or terrapin
Disease, old age, wounds, the usual.
A terrapin
No
yes
It help the terrapin to move its head immediately into its shell when predators are near or when they sense danger.
A terrapin is a form of turtle.
a terrapin comes in many species, but is a small turtle
A diamondback terrapin is an omnivore.