A pocket-maker. Nests on the surface of the ground, generally protected by surrounding, dense vegetation, or in deep moss. Nests are briefly described by Sladen (1912) and Winkworth Allen (in Stelfox, 1933). I have seen a nest which was established beneath a sheet of a grounded, wooden hording on duneland in south Wales. In Shetland, Morice (1894) often found nest burrows in unmortared stone walls. On Inishmore (Aran Islands, Galway), the species has been found nesting only in grass in meadows and rough pasturage by the sea, these on sandy soils just above sea-level, and in entirely exposed positions away from walls, high vegetation or any shelter whatever (Winckworth Allen in Stelfox, 1933). None have been encountered on this island in walls or in the grass among rocks at higher elevations. The colonies of this species are rather small, the total population of imagines of each nest at the peak of the season usually not exceeding forty individuals (Lie-Pettersen, 1901, 1905, 1907; Løken, 1961). According to both Sladen (1912) and Alford (1975), the comb is similar to that of B. humilis, but the colour is darker. They also consider this to be an aggressive species, the nest being defended pugnaciously. An occupied nest is illustrated by E. von Hagens (1986). A Norwegian nest of this species is described in detail by Løken (1961). The species seems to flourish best in cool, damp seasons.
This species has been observed establishing in abandoned Sciurus vulgaris nests (Hoffer 1884)