High densities of the yellow crazy ant have the potential to devastate native 'keystone'
species, resulting in a rapid alteration of ecosystem processes and negative effects on
endemic species. The most notable example concerns the native forests of Christmas
Island, in which populations of the yellow crazy ant have exploded in recent decades (at
least 60 years after its initial introduction) (CBD 2003). On the island the ant is
continuously active and realises a broad diet, tending honeydew-producing scale insects
(Tachardina aurantiaca) and causing their populations to explode (CBD 2003). This
results in an increased level of carbohydrate-rich honeydew residues on tree surfaces
and an increase in the growth of sooty moulds on trees and tree death (CBD 2003).