Breeding between April and July, the female Hawaii creeper constructs the nest in a tree cavity or on an open branch. Whilst she lays one or two eggs and incubates them, the male defends a very small territory in the immediate vicinity of the nest. However, once the chicks have hatched 13 days after laying, both the male and the female contribute to feeding them by regurgitation. After the chicks have fledged, the adults moult (4).
As the name suggests, this species creeps up and down tree trunks and along the underside of branches in search of its insect prey (3). It also consumes nectar, but whilst the availability of insects is constant, nectar is highly seasonal (4).