Female Megachile sp. ? bee from a colony of approximately one hundred individuals burrowing on an exposed sand track in coastal jarrah/marri/peppermint woodland. Here she can be seen in the process of excavating her nest. As she reverses out of the nest, her front legs are used to catapult a stream of sand grains through the hind legs, thus excavating and flattening the resultant sand mound at once.