Westwood's Ant

Stenamma westwoodii is a rusty-red/reddish brown, bearing resemblance to Stenamma debile, to the point where microscopic examination is required. Before 1990, it was believed to be the only Stenamma species in the British Isles, it is now thought that S. debile is far more common, and many earlier records to S. westwoodii are now treated as S. westwoodii aggregate. The body is covered in scattered pale hairs, laying flat on appendages. Workers are measured at 3.5 - 4.0mm, queens measured at 4.2 - 4.8mm with their wings having a yellowish tint and males measured at 3.8 - 4.5mm.

Stenamma westwoodii is native to north and eastern Europe, with some specimens found in areas as far east as Armenia and Georgia. The majority of the specie's population is in the United Kingdom, in the south of the country. Stenamma westwoodii's nests consist of up to 150 workers. The species is monogenous, meaning a single queen per colony. Their nests are often found in dry and well-drained woodland, nesting beneath deep stones, under moss and among tree roots.