small bugs in the tank

Question
We recently discovered some very tiny redish things running around on the sand of our hermit crab tank. They are very hard to see and we're not sure what they are. Can they be babies or are they some kind of bugs that grew in the tank and the sand? How do I take care of these and are they harmful to the crabs? Where can they come from? Please help as we are very concerned about our 4 crabs in the tank. Thank you.

Answer
They are a sort of bug, if they are not on your crabs (crab mites are white) you can remove the substrate or also take the food out for several days and it will cut back. Not to worry though, there are a lot of bugs around that are harmless to crabs, just sometimes troublesome to us!