The nests consist of separate chambers, each of which is occupied by a pair (sometimes with offspring) roost and breed. Nests are built around large and sturdy structures like acacia trees or sometimes even telephone poles. Large nesting colonies can be active across many generations, sometimes over a hundred years. The nest appears like a large haystack in the tree. If seen from below, entrances into the chambers may be seen, giving a honey-comb appearance. The entrances may be about 76 mm (3 in) wide and can be up to 250 mm (10 in) long. Sharp sticks may be placed to deter predators from entering.