Wild animals also love kissing, and they're quick to show their affection.

Wolves, Dogs, cats, birds and other animals display licking, nuzzling, and grooming behavior among themselves, but also towards humans or other species. This is sometimes interpreted by observers as a type of kissing.

The alpha male and alpha female within packs mate for life and share leadership roles and responsibilities caring for their young and other pack members. The alphas are typically the only ones who breed, but occasionally others, known as subordinates, will also mate.

Note: Affection in general has stress-reducing effects. Kissing in particular has been studied in a controlled experiment and it was found that increasing the frequency of kissing in marital and cohabiting relationships results in a reduction of perceived stress, an increase in relationship satisfaction, and a lowering of cholesterol levels.