Aboriginal people originally occupied Rottnest around 30,000 years ago. The island was originally connected to the mainland, but it eventually became separated with the Indian Ocean, and so it became an island. As Aboriginal people did not have boats, the island had no one living on it until the Europeans arrived. Dutch sailor Willem de Vlamingh named the island "Rattenest", meaning "Rat's nest". The 'rats' he was referring to was actually a Quokka, a native animal on the island. 