Usually observed low down in foliage or foraging for insects and small arthropods on the ground, alone or in small groups, the Blue-breasted Fairy-wren is easily confused with the Red-winged Fairy-wren M. elegans (south) and the Inland Variegated Fairy-wren M. lamberti assimilis (north), both of which overlap in range with the Blue-breasted Fairy-wren. The male of the Red-winged Fairy-wren has a paler, more silvery-blue, crown (dark blue in the Blue-breasted), while the female has a grey crown, and the male of the latter species has a black breast (again dark blue in the Blue-breasted) and the female has a grey-brown crown and less blue in the tail. As with most fairy-wrens, the Blue-breasted is sedentary. The nest is oval-shaped, with the entrance in the upper side, and is typically well-hidden in a low bush. Three eggs are typically laid in a clutch.