Just called, I asked if they might be different ages since the welsummers were more feathered out than the wyandottes, she said they all came in last week, so I'm assuming close to same age, then I asked what hatchery they use and she didn't know but put me on hold to find out,... it's Townline poultry. Just fabulous. So far I haven't noticed the first problem, they all seem healthy and happy, running around, eating and sleeping ok. Everyone has firm poop and no yucky butts, but I'm now afraid of infecting my old girls with something. They're almost four years old, so isn't that almost elderly for hens? The new chicks won't be going outside for several more weeks, and when they do there will be a fence dividing them because the big girls free range during the day but the new ones probably won't until close to summer. Should I be able to tell by then? Ugh this is so frustrating.