12 things you never knew about kissing but you really should.

3. Research Shows Our Love Of Kissing May Come From Rats

Researchers say that kissing descends from a species of ancient rats known as Eomaia scansoria. The ancient rat would kiss its mate by rubbing their noses together. The rubbing of noses gave the rats a sample of pheromones, as well as sent out signals of their sexual desires.

Scientists state that mice and men have a very similar genetic makeup. Mice, rats and men share a common ancestor that lived between 75 and 125 million years ago. The rat-like creature was called Eomaia scansoria. Scientists believe that the Eomaia scansoria rubbed noses with its chosen mate so that they could get a sample of pheromones and let them know of their desires.