My four 23 week old red stars seem to be happy and doing well with two of them laying daily. I noticed some tiny mites in the coop and cleaned it out and spread around alot of DE. I think i have killed the mites but now three of the hens are sleeping outside in the pen and not in inside. One hen still goes in every night. Is it the mites that made the hens start sleeping outside and how do I get the other three to go back in to the coop?