Some time in January, we put some foam insulation in our chicken run because it was going to be below freezing for a week. It fell to where the chickens could get it. They pecked at it for several hours before we noticed it and took it out. That day and the next, our egg production doubled. A few weeks ago, a piece of styrofoam roofing fell into the run and they devoured it. Again, for two days our egg production doubled. Today, they got into our neighbors scrap pile and destroyed an old styrofoam cooler. We doubled our eggs again today. I've searched the web and this forum and everyone says its an old wives tale. I'm not so sure. I don't intend to regularly feed my girls styrofoam (we try to be all natural and the chickens free range almost every day), but I think this is interesting results.