Hi there. My mom and I are having some trouble with our hens. We've had four hens die on us in the last month or so. They all seem to be weak for a few days before. Two of them were Belgian Bantams but I'm not sure about the other two. All of our chickens are fed chicken scratch and they eat what's in the yard when they roam during the day. When my mom asked the feed store what could be happening, the woman said it could be the cold. We live in San Diego county (Southern California) so it doesn't get too cold. There were a few nights in the December where we had frost advisories but they made it through those. We raised chickens for almost 19 years and we've never had so many die on us in so little time. Any suggestions or advice would be greatly appreciated. Thank you!