Handling
(source: http://members.tripod.com/~animalcare/hchandle.html)

This is the safest way to pick up your hermit crab

Handle hermit crabs with care. In the beginning, the easiest way to hold a hermit crab is by its shell to avoid getting pinched. After the crab begins to trust you more you can try putting it in the palm of your hand. Make sure to keep your hand flat. The crab might pinch you if it thinks it will fall. If a hermit crab pinches you, try not to panic, and hold it under running warm water to make it let go. Be careful never to drop the crab, which could kill it, and never attempt to take a hermit crab out of its shell. A hermit crab would rather be torn apart than be separated from its shell.