[4] It is the only member of genus Smicrornis; gene flow is strong and local variation follows Bergmann's and Gloger's rules.

[8] The tail feathers are brown with a black bar and white spot on the tip of all the rectrices, except the central pairs, which are completely dark.

[10] Four subspecies of weebill are currently recognised and exhibit slight variation in feather pigmentation, dependent on distribution.

They are most commonly found in the canopies of dry, open eucalyptus forests, woodlands and mallee,[12] occasionally coming down to the midstory to feed primarily on small insects and their larvae.

[7] Weebills forage busily in pairs, or small parties of up to 8, feeding mainly in trees, often hovering, they are active and noisy and cling to twigs while gleaning insects from the outer foliage of the canopy and midstory.

[15] The dome-shaped pendant nests of weebills are made from fine, pliable materials, such as grasses and plant fibers suspended from a branch and concealed in dense foliage of the tree canopy.

[15] Weebills are known to utilize cobwebs, insect cocoons and animal hair to bind, strengthen, and further conceal the nest.

Courtship displays have been observed in weebills, where males ruffle their cheek and head feathers with outstretched wings to the female.

It is thought that male and female weebills display to each other at the nest-site with tail-fanning, slight bowing and wing quivering.

[16] Widespread and common in its habitat throughout its range on mainland Australia, the weebill is evaluated as Least Concern on the IUCN Red List of Threatened Species.