My hens are 10 months old and stopped laying about 2 weeks ago. We did lose a hen about the time they stopped laying, so I assumed the stress from that and the heat (I live in dallas) contributed to it. After looking up some other possibilities, I saw that mites/lice can cause them to stop. I checked them today and noticed that one of them was missing some feathers on her chest but all the others look fine. I’ll add pictures of a couple of their vents and my ones chest to get some advice.