Look for dull greenish color, with blue or whitish spots or granules covering body.
Antennae are orange and unbanded.
Hermit crabs grow and need to move into larger shells from time to time. Sometimes they stay in their old shell too long and look like someone whose pants are too small!
Hermit crabs can be carefully handled. When you pick one up, it will quickly retreat into the shell, but if you are still, it may venture back out. Its claws are not big enough to cause anything more than a little tickle.
See other small hermit crabs Blue-handed Hermit and Hairy Hermit, which is the most common shoreline hermit.