I have a chance to add what appear to be (from photos) 3 healthy New Hampshire Reds to my flock tomorrow. The seller lives about 30 minutes away. I have 12 hens already, plan on keeping these 3 separate for a week or so. They are about the same age as what I have (20-30 wk old RIR, BA). How do I check for frostbite? I've done some reading, but it always seems you folks do a better job explaining. Also, any other dead giveaways/red flags for health problems? The seller hasn't given me a reason to distrust, I just want to make sure I'm doing the best I can to add to my flock. Thanks in advance for reading and responding.