The Barn Swallow (Hirundo rustica) is in the family Swallows/Swifts and is a sleek, agile bird known for its distinctive forked tail, glossy blue-black upperparts, reddish-brown throat and forehead, with creamy underparts. These migratory birds build mud nests in barns and other structures, favoring open countryside and farmland. Barn Swallows are highly social, often forming large flocks during migration. They are in the family Swallows/Swifts.