I remember when I was young, many years ago (I love saying that) and we had chickens in the garden mainly for eggs, but we did eat some at Christmas (sorry RATTER) there was a mouse's nest (should that be mice's nest, since there was more than one mouse?) in the chicken run and we saw one of the hens catch one and eat it - it was very small, probably a baby one. The hen didn't care what she had to eat - anything that was going I reckon. The next egg she laid went to my father, nobody else fancied eating it.