Animal Odd Couple

An old photo of my childhood dog and pet chicken. This picture was taken shortly before their deaths. Both lived to be nearly 20 years old, sharing not only yard space, but also a hut, as well as food and water. For roughly 5 years they coexisted, not merely tolerating each other's precense, but actually mutually benefiting from one and other. The hen would groom the dog and keep most pests at bay while the dog would allow the hen to lay eggs in the same box they slept in. They would also eat from the same food dish, at the same time! All this and not a single conflict or act of aggression from either, ever!