I don't know a lot about this; I'm breaking my head trying to think of an answer. Probably mites. I would do a complete cleaning. Wash it out, change the substrate, pick out as many mites as possible, anything you can. I heard some B.S about how they never go away, but they can stay at a manageable amount. Can't help you with that. I would just go a head and clean the container, but you may want to wait for a second opinion.
If they not the whole substrate full, & only by the cricket remains and a bit on the wet substrate, thats ok! when you remove the cricket remains alot of them will be removed aswell! but if the cage is full! then yes deff do a new setup for your T!
Remove all the sub. They will start to feed on the soft spots by the joints on your T when the food runs out. I just picked a bunch off my .5" A. versicolor. I had a .5" T. gigas die yesterday because of the mites. My first mite related death. :wall: It is not known exactly how they kill them but it can. Try your best to keep your slings free of them. They can be a huge problem and once established on your T, hard to get rid of and remove. Let the sub dry out for a couple days inbetween watering or misting. Best of luck.