Kissing is a big part of human culture. According to ancient cuneiform tablets found in Iraq, humans have been smooching since at least 2500 B.C. Around the world today, many societies share kisses in some form or another, whether it's for romance, familial love or a friendly greeting.
When a behavior is so widespread, it makes sense to wonder whether other species do the same and if the behavior has an evolutionary origin. So do any other animals kiss?
