Myrmica

Myrmica is a genus of ants within the subfamily Myrmicinae. It is widespread throughout the temperate regions of the Holarctic and high mountains in Southeast Asia. The genus consists of around 200 known species, and additional subspecies, although this figure is likely only to rise as soon as Chinese and Neartic fauna lists are revised. The genus contains a number of inquiline species (commensal symbionts), other Myrmica species that manage to invade the nest of their host. Subsequently, they use hormones to manipulate the host colony in such a way, that eggs of the host queen develop into workers, and parasite brood into sexuals. Hence, the parasite is not able to sustain a colony of its own, but uses host resources instead.

Similarly, larvae of the butterfly genus Maculinea (Lepidoptera, family Lycaenidae) live inside Myrmica nests where they are either directly fed by ants or prey upon ant brood. The five European large blue butterfly species are facing extinction and are subject to large conservation efforts.