No eggs

I've just been out to collect eggs, I havent any again. Have only had 2 in 3 days from 12 hens. Any ideas as to why?

We did have red mite but Im pretty sure I managed to get rid, Will check again later though. They dont seem stressed, nothing's changed and no sign of illness. A lot more feathers than normal though so maybe they are starting to moult. This is my first autumn with hens so havent experienced a full moult yet. It could be that.
Also the weather and approach to autumn. They have been putting themselves to bed about 7.30ish

I found 1 stray duck egg but no hens eggs  Hopefully its just the moult / weather 

out of our 8, 2 have never laid, 2 lay very sporadically, the other 4 usually give us an egg every day but so far today there's only 2 eggs from the bantys