Excavator: Ground. The species characteristically nests in aggregations on light, sandy soils. Mainland Scottish sites consist of duneland. At Torrs Warren (Dumfries & Galloway), for example, A.B. Duncan (pers. comm.) found it on both the mobile foredunes (Ammophila arenaria zone) and on the stabilised dunes behind, an observation confirmed by C. Fiedler (pers. comm.) on Islay in 2008. In the Western Isles, it also frequents both these dunes and the dry, coastal machair (a maritime grassland unique to the Hebrides and parts of Ireland, and comprising a floristically rich sward established on wind-blown shell sand). Within the latter zone, on Barra and South Uist, it has been observed nesting on gently sloping, sandy hillocks with a southern or south-west aspect (pers. obs.). Irish habitat includes sandy clays along cliffs, marram dunes and, formerly, in the interstices of the masonry of a bridge (Stelfox, 1927, 1933). In Ireland, nest burrows have also been found on an exposure of flat loose sand within a pine plantation in Co. Wexford (pers. obs.).