Myrmica rubra, also known as the European fire ant or common red ant, is a species of ant of the genus Myrmica, found all over Europe and is now invasive in some parts of North America and Asia. It is mainly red in colour, with slightly darker pigmentation on the head. These ants live under stones and fallen trees, and in soil. They are aggressive, often attacking rather than running away, and are equipped with a sting, though they lack the ability to spray formic acid like the genus Formica.
This is one of the most common and widespread Myrmica species of the Palaearctic. It occurs in the region stretching from Portugal to East Siberia (as far as Transbaikalia), and from northern Greece to the forest-tundra zone in the North. It is also colonizing Japan and North America, where it is considered a nuisance and an invasive species.
These ants are very common in Europe and live in meadows and gardens. They live on a diet of honeydew excreted by aphids and feed on many types of insect and other invertebrates. They will attack any creature that disturbs their nest, but are not as aggressive as the red imported fire ant. They also consume pollen, a phenomenon rarely documented in ants of the temperate zone.
This ant’s colonies have a polygyne form and can include up to one hundred queens per nest. These queens will have gathered together after their nuptial flight, formed a nest and laid their eggs in it. The species is also polydomous, with many nest sites per individual colony. The queens can live up to fifteen years. Nuptial flights take place normally in late July to mid-August in Europe. Hundreds of young queens and males take to the air to mate together. Afterwards, the males die and the queens shed their wings to make a new colony. No nuptial flights have been witnessed yet from this species where it is living in North America, however male-only mating swarms have been recorded in Newfoundland, Canada.
The ants explore the surrounding area around their nest and look for materials, both plant and animal, to feed their colonies. When they find dead bodies, undertakers pick up the dead bodies and quickly carry them away from their nest up to 3 metres (9.8 ft) away. They choose locations randomly, and so this species does not create cemeteries.
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 (a junior synonym of Phengaris, family Lycaenidae) and of the southern armyworm, live inside Myrmica nests where they are either directly fed by ants or prey upon ant brood. This parasitism is employed primarily by specific species such as Phengaris arion forming predatory relationships.