Lasius emarginatus is a fairly common warmth-loving ant found in much of Europe including the Channel Isles but only recently discovered in mainland Britian. It looks similar to the common black ant L. niger (Linnaeus) except for its distinctive orange/red alitrunk contrasting with its dark brown head and gaster. It could, possibly be confused with L. brunneus (Latreille), which is also bi-coloured, but it is a much bolder species. Unlike the furtive L. brunneus, L. emarginatus can be found running around on open ground. Under the microscope the antennal scapes of L. emarginatus can be seen to have outstanding hairs unlike the scapes of L. brunneus.
Found throughout the Channel Isles. Not known from mainland Britain until a colony was found in Islington in 2008. Since then there have been more records from London and a few isolated records from other parts of England.
Found throughout central and southern Europe and around the Mediterranean.