They certainly could. Ravens have been known to kill small pets.
Yes, bobcats kill and eat chickens.
You can't. That is impossible. The only way to get feathers on Minecraft is from chickens.
2207 chickens
it can transfer diseases to human like bird flue ... !
Not if you mean "man-eating chickens" Chickens, being omnivores, will kill and eat small rodents and other animals. So the answer is yes, chickens can and will kill for food.
No.
people
Generally, predators kill chickens. Not prey. :P Most medium sized carnivores will kill chickens. Dogs, foxes, coyotes, weasels, etc. Not sure about cats, but they could probably kill bantams with no trouble.
We eat the cows and chickens. They are food. The same cannot be said of cats and dogs in most cultures. In most cultures we do not kill pets, not even when they are cows and chickens.
They aren't really, but ravens like to scavenge, and a wolf returning to continue feeding on an earlier kill probably won't like seeing ravens there eating from it.
Yes, raccoons will kill and eat chickens if they are not well secured.