We had a flock of 12 red sexlinks and I made the mistake of buying 5 Americana pullets and putting them in with the flock. They kept laying for a while and the Americanas did also. But, we lost several hens to predators - racoons, coyotes, bobcats, something or things. So they experienced considerable trauma. (Most of them were killed and taken completely away during the day time when we were not at home. Now we are down to seven sexlinks and they haven't laid for about a month. Some of them molted and that affected them, but that seems to be over but they still aren't laying. Days are short this time of year so I put a light on a timer in the hen house to see if that would help. So far - no change. All of them spend a good part of the day outside so they aren't broody and they look as healthy as ever. Any suggestions for getting them back on the ball?