This affectionate pair of Atlantic puffins know a thing or two about the restorative pleasures of kissing, which we are celebrating today on International Kissing Day. Started in the United Kingdom, the holiday went global about 20 years ago as a yearly reminder that kissing isn"t reserved just for greetings or social formalities. Puffins engage in an endearing form of courtship behavior seen here called billing, in which they playfully tap each other"s beaks by swinging their heads from side to side.