There are mites. whether they are harmful, I can not say, but probably yes. how big is your colony? is it possible to relocate them somewhere in? if so, then do the cooking and all objects with hot water. wipe everything where the mite could be on it thoroughly, several consecutive days down until you later can not see any more.
at best you see you at your ants and the nest just yet. if there are mites in it, you have to relocate. make sure that no feed residues or other soiling form in which the parasite or from which they could feed themselves, lying around.
i hope you understand me, i wrote this text with google translator...
good luck!
lg, doc