Sicus is a small but distinctive genus within the family Conopidae, represented in Europe primarily by the species Sicus ferrugineus. Flies of this genus are medium-sized and immediately recognisable by their uniform reddish-brown to chestnut coloration, which sets them apart from the more boldly patterned conopids. The head is large and rounded, typical of thick-headed flies, and the abdomen is elongate and slightly constricted at the base.