[citation needed] They live in Europe, from Spain to the Caucasus; populations in North America are now considered to be a separate species, Lasius americanus.

[5] This mutualistic relationship benefits the adult butterfly by reducing the need for parental investment.

[5] Once the eggs hatch, the ants chaperone the larvae, averting the attacks of predatory organisms like wasps and spiders as well as parasites.

In return, the ants receive a saccharine secretion fortified with amino acids from an eversible gland on the larvae's back.

[5] Once the larvae become pupae, the ants continue to provide protection against predation and parasitism.