These birds, like all Honeyguides are brood parasites. Single eggs are laid in the nests of Woodpeckers, Barbets, Starlings and other hole-nesters. When the young Honeyguide hatches it has a vicious membranous hook on the bill which it uses to despatch its nestmates rather ruthlessly!
Immature Honeyguides have a prominent pale yellow area stretching from chin to chest. Strangely they dominate adult Honeyguides at bee nests.