Kissing seems to be a uniquely human activity but some behavior in the animal kingdom comes pretty close. Here are just a few examples.
Image: picture-alliance/Anka Agency/G. Lacz
Gregarious cats
Most cats are loners. But lions and cheetahs are an exception. When they meet, the fast cats with the dotted fur sniff each other, groom one another, rub their cheeks (like the cheetahs pictured here) and lick each other's faces. Quite cuddly, aren't they?
There's no love lost between these guys. The elephants are actually trying to bump each other out of the way in a fight over who gets to drink from a water hole in water-starved South Africa.
Image: picture-alliance/blickwinkel/P. Espeel
Say hello to my little friend
It may look a lot like a lovers' tryst, but these marmots aren't kissing either. This is a friendly gesture, however. When they meet, marmots greet each other by putting their heads together and rubbing noses.
Image: picture-alliance/Mary Evans/S. Meyers
I'm a fighter, not a lover
These lip-locking gourami fish may look cute, but they are actually fighting. Nonetheless, this "kissing" behavior makes them a popular Valentine's Day gift in China.
Image: picture-alliance/dpa/Imaginechina
Scent of a...hare
Yep, no kissing here either. These hares just get close to sniff each other. Usually, hares are solitary or live in pairs and are quite shy. And fast! They can run as fast as 56 kilometers per hour (35 mph). Jackrabbits can dash even faster.
Personal scent is one of the most common reason for animals to stick their heads together. Case in point: the gray seal pictured here. Catching a whiff helps the animals identify each other.
Image: picture-alliance/blickwinkel/McPhoto
Biting?
These two orcas look more like they're biting than kissing. We don't know what happened after the photo was taken. Orcas don't attack each other in the wild, although there have been cases of biting and injuries in captivity. We can only hope that wasn't what happened here.
Image: picture-alliance/Anka Agency/G. Lacz
Just bill me
It's somewhat difficult for birds to kiss given their beaks. Instead, they touch or clasp bills. The behavior probably came from mouth-to-mouth feeding and can range from tender touches to violent clashes.
Image: picture-alliance/dpa/F. Lanting
Till death do us part
This looks like quite a passionate exchange and chances are that it is. Parrots are picky about their mates but once they've made up their minds, they stick together for the rest of their lives. Quite romantic, isn't it?
Anthropologists are still divided over the origins of kissing. A commonly held belief is that it grew out of kiss feeding. That's the practice of one individual chewing food and feeding it to another who is incapable of breaking it down themselves. Animals usually do this mouth to mouth.
At the same time, kissing isn't a universal human activity either. A survey of 168 cultures found that kissing is common in 46 percent of them.
But there are certainly many animals that display behavior that could be mistaken for kissing. Check out our gallery to find out more.
