Around-nest 'cemeteries' of Myrmica schencki Em. [Hymenoptera: Formicidae]: their origin and a possible significance

Unusual rubbish piles of Myrmica schencki Em. colonies nesting within territories of Formica polyctena Först. are described. The piles tightly surrounded M. schencki nest entrances and consisted mainly of remains of F. polyctena corpses (with a small addition of corpses of other local ant species) previously collected as food by M. schencki foragers in F. polyctena waste disposal zones. This observation shows that, under certain conditions, M. schencki can actually be a specialised myrmecophagous scavenger. The peculiar finding of M. schencki rubbish piles, in connection with other observations of using dead bodies and other remains by ants, suggests that such piles can play some role in interspecific relations in ants. This possibility is considered in the context of the competitive hierarchy of ant species.