The sittellas are small woodland birds with thin pointed down-curved bills, which they use to extricate insects from bark.

The true evolutionary affinities of the sittellas have long been clouded by their close resemblance to the Northern Hemisphere nuthatches.

[2] As late as 1967 the sittellas were retained in that family by some authorities, although doubts about that placement had been voiced in the previous decades.

Today they are afforded their own family in a clade close to the berrypeckers and longbills (Melanocharitidae) and the whistlers (Pachycephalidae).

The species was described from a distal tibiotarsus discovered in the Riversleigh World Heritage Area in northwestern Queensland, Australia.

The family has a generally weak flight, which may explain their inability to colonize suitable habitat on islands like Tasmania.

The legs are short but they have long toes, but in spite of their lifestyle they show little adaptation towards climbing.

They have short tails and are between 10 and 14 cm in length and 8 and 20 g in weight, the black sittella tending to be slightly larger and heavier.

The sexes of some subspecies have entirely black heads, other white, and others dark crowns and paler throats.

The sittellas are generally highly social, usually being found in groups of five or more individuals and only more rarely in pairs.

Studies of varied sittellas in New South Wales suggest that they live in clans of eight to twelve individuals and defend mutual territories against other groups.

The diet of the black sittella has, like other aspects of its biology, been little studied, although the stomach contents of one that were examined contained caterpillars and spiders.

[8] Sticks were used to pry boring beetle larvae out of cavities, in a similar fashion to that of tool using woodpecker finches of the Galápagos Islands.

Nest building duties were shared amongst the group, and the speed of construction depended on how many birds were involved.

Nests are usually placed in the prong of two branches, and is a deep cup decorated in the bark of the tree it is built in, thereby camouflaging it.