slow molt or somebody pulling feathers??

ok so my 3 hens who had been giving me at least one egg a day each some times 2. have desided to stop laying.. (unknown age bought as laying age hens) sexlinks....they dont apper to be less any feathers but there are feathers everywhere in the coop. (there are other chickens in there too) could the feathers be theres and they just dont look like they are missing any. and the no eggs is because of molting?? or could it be some thing else.
we have been pulling other hens/pullets and immature roos out of that coop as we get that breeds coop/run done.(trying to get breeds seperate for breeding) could the subtaction in other chickens be doing this?? the bantum hens where moved to their own coop and they stopped laying too. the silkies dont seem to be effected as they have stuck to ther laying schedule even after being moved.