Wallace's giant bees build communal nests inside active nests of a tree-dwelling termite. This may have hidden their existence even from island residents. The bee uses tree resin to build compartments inside the termite nest, which protects its galleries. Female bees leave their nests repeatedly to forage for resin. The bee's large jaws help to gather resin: the female makes large balls of resin which are held between the jaws. The association of the bee with the termite may be obligate (it must live there).