They are communicating. Crabs use their antennae to sense the world around them. By touching each other, they are finding out who is next to them and what they are doing.
first the hermit crabs mothers lay eggs then the eggs hatch and as soon as the eggs touch salt water, they burst open intobaby hermit crabs. Then they arelarvae. Then they grow in to adults and find a shell to live in.
Yes land hermit crabs do lay eggs if you suppose to have a sot of digged up spot in the tank check for a egg but watch out if you touch the egg the mother will not sense that the egg is hers and hermit crabs carry a disease called salmonella so do not touch 
No crabs don't know their babies - they release them into the sea while they are still microscopic.
touch all types of crabs in the touch pool,trade for it,or have someone send you one.if you wanna know if anyone is tradeing one,Monkeyjams is.
all you have to do is touch the animals and fill up the bar. dont make any ripples for the hermit crabs or else they will did under the ground.
Like snails, it is incredibly difficult to humanely get the shell off hermit crabs and ensure they'll still live. Also, because of the fact they have an exoskeleton (skeleton on the outside), injecting needles cannot get through to their innards. They hide when you touch them, plus they're quite small compared to most pets.
Hermit crabs don't experience love in the way humans do, but they do engage in social behaviors and bonding. During mating, male hermit crabs will perform a courtship display to attract females, which may include waving their claws or engaging in gentle touch. After mating, females can store sperm to fertilize their eggs later, indicating a level of reproductive strategy rather than emotional attachment. Their interactions are primarily driven by survival and reproduction rather than romantic feelings.
Unlike humans who have a big brain and lots of nerves to send signals down the body, the hermit crab and other crustaceans have a much more primitive system. They have a primitive ventral nerve cord and ganglia system similar to an earthworm. Hermit Crabs have good vision thanks to their compound eyes on stalks (although can't look below them) and sensory organs are found on the body. Like true crabs, hermit crabs have bristles and hairs all over their body - but mostly on their walking legs - which act as touch receptors. The long antennae of hermit crabs - longer than other crabs - have smell sensors, used to find their food. Smell detectors are also found on the legs. When a hermit crab walks over food, its legs smell it, and the chelipeds quickly grasp it and move it into the mouth.
The most common "illness" (not including lack of proper care) is called Post-Purchase Stress (PPS). Hermit Crabs are very very very difficult, almost impossible, to breed in captivity, so all hermit crabs found in pet stores are wild caught. The stress of being plucked from a beach, forced into a deadly painted shell, being shipped off to a pet store where they are poked at by children, and trying to adjust to a plastic cage full of pink sand and wet sponges (this, sadly, is the most common, though very incorrect, set-up I have seen) kills many.
HERMIT CRABS TAKE OTHER CREATURES SHELS SO THEY CAN PROTECT THEMESELFS BECAUSE THEY DONT HAVE SHELS OF THERE OUN THEY USE IT SO THEY CAN HIDE FROM OTHER CREATURES THAT WANT TO EAT THEM SOME EVEN USE ENEMENI WHITCH IS A KIND O SEA PLANT THAT STINGS U WENE U TOUCH IT THE APLY IT ON THE SHELS THEY FIND
I've heard of hermit crabs being bred in the lab (I'm not aware of official documentation, however), but no home setup would be able to handle it. The life cycle of a hermit crab is far too complex; you can't just throw a male and female crab in 10 gallon aquarium and wait to see what happens. The process is very tedious--even if you were able to provide the proper setup for breeding, you would have to sustain the offspring for months until they were even close the the size of the hermit crabs at pet stores (not to mention your responsibility for the adult crab!). No average person has the time or money to do this properly.
Some hermit crabs can be picky, and a few of them will not touch store bought crab food. Try introducing some fresh foods, like non-salted boiled egg or fresh washed fruit. They only need very tiny pieces. It will not appear like they are eating much. Throw out what they do not eat each day.