Puppy Love: Nettle, a mother dog, never worried when she needed a break from her pups. A chicken named Mabel was happy to take over as surrogate mom. Brought to live inside a farmhouse in England after a horse stepped on her foot, Mabel would fluff up her feathers, plop down on top of her brood of pups, and tuck them under her body as if they were chicks.
Horses during courtship, mature stallions and mares sniff, nuzzle, nicker, and even nip at each other.
Pigs, which have been living side by side with humans for some 9,000 years, cooperate in social groups known as sounders.
* National Geographic ~True Love: Surprising Photos of Animal Affection.