Excavator: Ground. Nests in aggregations, some extensive, in firm sandy and usually sparsely vegetated soil.
A Danish nest has been described and figured by Munster-Swendsen, 1970) is very unusual in having two descending curved entrance burrows which connect below, forming a U-shaped burrow. The first of these to be dug is used solely for excavated soil (which eventually completely fills it), its entrance characterised by a tumulus formed from this soil. The second borrow is soil free and its entrance is devoid of a tumulus. It is the latter burrow which the female uses to gain access to the nest. The main, more-or-less vertical burrow is initiated at the point where the two curved entrance burrows meet. Two lateral burrows arise from the lower end of the main shaft and these deeper burrows may divide, each branch leading to an oval cell. A completed nest may contain up to ten cells. In large nests a further entrance burrow may be dug which is used to accommodate the soil from deeper excavations. The cell wall is smooth and coated with a shiny, wax-like lining. Immature stages (excluding pupa) are also described by Munster-Swendsen; he noted that the winter is passed as a prepupa. This author also describes the nesting biology and some ecological aspects (Munster-Swendsen, 1968). The larva has also been described and figured by Micheli (1931).