Hello! We have 4 hens, 2 Australorps, a Maran, and a California White. We're new to chicken-keeping, and have had them since April. When I was researching raising chickens, I read somewhere that most breeds are fine down to 0 degrees Fahrenheit. We live in metro Denver, Colorado, and it only gets that cold a few times a year (so far 3 times this winter). After weighing the pros and cons of heating the coop (frostbite vs. fires, etc) we decided to put a heat lamp on when the temperature goes below zero. Each time it's gotten below zero and we have put on the lamp, our chickens fight with each other! It's been a different chicken with pretty nasty pecking injuries each time, and I've never seen them fight or end up with pecking injuries any other time. They are usually chicken BFF's. So, I am wondering if you all have any thoughts on why. Is it because it's so cold and they don't like to go into the run and are cooped up (ha), or is it because the heat lamp makes their coop perpetual day and they're going nuts? Thanks!