We had a pair of free-range, laying Isa Browns who could always be seen scratching around all over the place together. Then one of them was killed by a feral cat. The evidence was feathers, some of them bloodied, laying in the garden, and plenty of paw prints in the wet earth. The surviving hen was standing alone at the back of the house. Later that day, I saw the survivor picking up the feathers of the dead hen in the garden. Then she started to call out like she was calling the other hen. If I did not see and hear it myself, I would never have believed it. At the risk of sounding like a soft old git, that's one of the most surprisingly sad events I've personally witnessed. She is still giving eggs, but now spends most of her time sitting around. Her behaviour is markedly different. I already abstain from most animal products. If I did not, this would have inspired me to get started. As it happens, I now feel more motivated to abstain completely. As for our solo hen, she'll get some new company as soon as I make them a safe area to scratch around in.