Anoplolepis gracilipes (so called because of their frenetic movements) have invaded native ecosystems and caused environmental damage from Hawaii to the Seychelles and Zanzibar. On Christmas Island in the Indian Ocean, they have formed multi-queen supercolonies. They are also decimating the red land crab (Gecarcoidea natalis) populations. Crazy ants also prey on, or interfere in, the reproduction of a variety of arthropods, reptiles, birds and mammals on the forest floor and canopy. Their ability to farm and protect sap-sucking scale insects, which damage the forest canopy on Christmas Island, is one of their more surprising attributes. Although less than 5% of the rainforest on Christmas Island has been invaded so far, scientists are concerned that endangered birds such as the Abbott’s booby (Sula abbotti), which nests nowhere else in the world, could eventually be driven to extinction through habitat alteration and direct attack by the ants.