Is it that monkey's are evolving at an increasing rate or that humans have gotten over some of their superiority complex and can see the intelligence in other animals?
Female monkeys living in a 250-strong colony were observed by scientists teaching their young how to use strands of hair to clean between their teeth.
The theory that primates are able to teach offspring how to use tools was confirmed by the discovery, according to Professor Nobuo Masataka of Kyoto University's Primate Research Institute, who conducted the study.
"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," he said.
The study focused on the observation of seven female long-tailed macaques and interaction with their off spring at a colony of monkeys near Bangkok in Thailand.
The practice of teeth flossing doubled and became significantly more elaborate when they were in the presence of infant monkeys, suggesting that they were attempting to teach the technique to the young.
"The study is still at the hypothesis stage," said Professor Masataka.
"We would like to shift our focus to the baby monkeys to check whether the mothers' actions are effectively helping them learn how to clean their teeth."