Summary:
A capuchin monkey is known for its teeth gnashing of teeth.

Full article:
They're some of man's closest relatives. But this little Capuchin monkey has taken aping human behaviour up a notch. When his keeper hands him some dental floss, he does what we all need to do more of - he gives his gnashers a thorough floss. In the wild, Capuchin monkeys, known for their intelligence, spend  days searching for food and napping, wedged between tree branches. But this cheeky pet monkey, who goes by the name of Boo, is more accustomed to taking care of his personal hygiene. What's this for? The little Capuchin monkey curiously examines a piece of dental floss . I know what I'm doing: But he soon gets the hang of flossing, doing a better job than many humans do . His owner, whose voice can be heard in the video clip, encourages the monkey, saying 'Floss your teeth Boo,' and 'get them nice and clean, get in between all of them.' 'Great dental hygiene, Boo,' he encourages as the monkey completes the job. 'Get between all of them,' Boo's owner tells him as the monkey concentrates on the task .