Flossing teeth

Source: nu.nl
The dentist always urges us to floss our teeth. But there are also macaques that floss. This was discovered by Japanese scientists. One macaque started this and taught the trick to her group members.
Researchers from Kyoto University conducted their study in the Iwatayama Monkey Park zoo. A macaque named Chompe seems to floss her teeth after every meal. She does this by chafing her teeth on the fur of the other monkeys or by pulling hairs from her own fur and using it as floss. The researchers think that this behavior was created accidentally. Macaque monkeys regularly lick each other’s fur to remove parasites. A hair probably got stuck once between Chompe’s teeth causing remnants of food to get stuck on it. She could then lick off food remnants from the hair. The reward of being able to lick food off the hairs probably caused her to repeat the behavior.
Very slowly, during a period of four years, the flossing ritual was taken over by other group members. In macaques new finds spread via close relatives. Mothers transfer them to their offspring. The flossing behavior spread very slowly because Chompe only has two close relatives in the group, her mother and one child.

The results of this research were published in the scientific journal Primates.