While terrapins don’t like to be handled, you can do some things to help make them feel more comfortable by building trust with them. Make sure to always approach your terrapin from the front as they might get frightened and bite if your hand appears from nowhere.
You can also learn to tell when they’re hungry. One way is that they’ll spend more time around the area where you normally place their food. Another way is if they stare at you for long periods.