Primatologists think they've observed Thai monkeys demonstrating tooth flossing to their infants:
"I was surprised because teaching techniques on using tools properly to a third party are said to be an activity carried out only by humans,'' Professor Nobuo Masataka of Kyoto University's Primate Research Institute said today.
His research team observed seven female long-tailed macaques and their offspring and monitored how often the mothers cleaned the spaces between their teeth with strands of human hair, in a colony of 250 animals near Bangkok.
The study found that the frequency of teeth-cleaning roughly doubled and became more elaborate when the infant monkeys were watching, suggesting that the females were deliberately teaching their young how to floss, he said. [Daily Telegraph]
The researchers plan to follow up with the baby monkeys to see if these flossing displays actually help them learn.