Hamerkops build massive elaborate nests, 1.5m deep and equally broad, with a mud-plastered entrance tunnel in the bottom. The very strong structure may take weeks or months to be completed. Several of these structures may be built by the same pair, that will use only one of them. However, owls may force them out and take over the nest. Other unused nests will readily be taken over by bees, other birds or even snakes and genets.