bugs in tank

Question
I just found that my Hermit Crab tank had little itty bitty bugs in it (a lot of them).  The bugs were in the food dish, and on the edge of their pool, but not on the crabs or near the hut.  What are they?  How did they get in there?  I put the crabs in another tank until I can thoroughly clean the bug infested tank out.  Anything else I need to do?
Thanks,  

Answer
Dear Felicia,
thank you for your question.
Most bugs that get into the crabitat are harmless or even beneficial because they will help with keeping the tank clean by eating crab poop, leftover food and even mold spores.
Springtails are often found in tanks:
http://www.wnrmag.com/stories/1998/dec98/snowflea.htm
They look like little commas jumping around in the tank and often on the water itself.
Booklice are another common insect species, they look like walkign grains of sand and they are very hard to get rid of because they live in almost all houses anyway,but find ideal conditions on the tank.
http://www.kcl.ac.uk/ip/bryanturner/other/index-psocids.html
Both are harmless and can stay in the tank unless you are bothered by them. A deep clean (change the substratem bake or boil all the toys/furniture) will get rid of them, but the booklice may be back again.

Food mites (that's my name for them, I don't know what species they are) are also harmless because they just eat the crab food but can multiply so much that they turn into a nuisance. They are whiteish-grey and round and are usually only in the food dish. Again, a deep clean will remove them from the tank.

The bugs are brought in with new toys or already live in the house or they come from outside. There's not that much you can do to prevent it, busg will turn up in crabitats now and then, but usually it's not a real cause for alarm.
I hope I was of some help to you
Jennifer