Well, I am with Nyboy on some of this . . .
Snakes? I have always enjoyed the beauty of their skins. If the chickens want a closer look at them . . . that isn't likely to bother me. I've eaten frog legs. There are other lines that shouldn't be crossed.
It's rodents ~ shudder ~ ! I don't have problems at all with bunnies or hamsters. Mice! Rats would be even worse! I used to trap muskrats in our irrigation ditches. At least, they seemed somewhat clean. Mice can run up your pants leg . . ! There have been reports of such things happening.
No self-respecting laying hen of mine would be welcome to eat a mouse. And, yes - I've seen them do it! I just had to put it out of my mind.
I get mighty upset when I see a hen eating her egg. I've never had to kill a hen because it has cannibalized eggs but certainly would if it came to that. There's always been another solution: chickens are happy to lay eggs in a dark nest and what they can't see, they won't eat. If the feather-brains start eating eggs, there's something wrong with the nest.
Steve