The genus is notable for the complex social organisation of its species, which live in colonies that can be further subdivided into coteries and nest contingents.

The four species are stockily built honeyeaters with rounded wings and yellow bills.

One of their most obvious characteristics is a patch of bare yellow skin behind the eyes, which gives them an odd 'cross-eyed' look.

[2] However, DNA sampling in a 2004 study by Amy Driskell and Les Christidis showed that the genus was most closely related to the New Guinea genus Melidectes, and that cooperative breeding evolved independently in more than one lineage of honeyeater.

The latter had been previously classified as a separate genus, but reclassified within this one by German ornithologist Hans Friedrich Gadow in 1884.