Welcome back to the world of ants. On our recent hikes, we encountered a beautiful and sometimes controversial species quite common in Europe: Myrmica rubra, known as the European fire ants or the common red ants. On that note let’s get a quick overview!

Identifying European fire ants, scientifically known as Myrmica rubra, can be quite challenging as they are tiny and nest under leaves and rocks. These ants are typically 4 to 5 mm in size and exhibit a yellow and brown coloration that gives them a distinctive reddish appearance, which is reflected in their Latin name “Rubra,” meaning “red.”

When observed in direct sunlight, these ants appear golden and somewhat translucent, while in the shade, they take on a darker, bronze-like hue. Their bodies feature grooves running from the head to the thorax, giving them a unique, almost tribal look.

A closer inspection of their head reveals a triangular shape adorned with golden hairs and a long, thin scape, which is the first segment of their antenna. Their petiole, or waist, is divided into two parts, with the last node seemingly merging with the abdomen. The abdomen itself is covered in fine, light hairs, which actually extend over their entire body. Additionally, their legs are lighter in color compared to the rest of their body.

It’s important to note that these ants are equipped with a stinger, making them capable of defending themselves effectively. So, while they may be small and intriguing to observe, it’s wise to handle them with care.

European fire ants, or Myrmica rubra, are native to Europe and thrive in temperate climates. Over time, they have spread to North America and Japan, often hitching rides via human trade routes.

Typically, these ants prefer wet meadows and gardens in Western Europe. While they can be found in forests, this is more common in Russian and Eastern European regions. They favor nesting in humid soil near rivers or swamps and do not require high temperatures to complete their life cycle. This adaptability allows them to survive in simple ground holes and even withstand short-term floods.

These characteristics make Myrmica rubra a potential invasive species, as they can endure various conditions and rapidly establish new colonies. Being eurytopic, they can live in a wide range of environmental conditions, further enhancing their ability to spread and thrive.

Finding the nest of Myrmica rubra, or European fire ants, can indeed be quite challenging!

These ants are highly mobile and can quickly relocate if necessary, showcasing their impressive survival skills. They are both polygynous and polydomous, meaning each colony can house multiple in this case up to a several dozen queens and the nest can be spread across multiple locations.

In sandy soil, their nests typically do not go deeper than 1 meter. In regular soil, they usually dig about 20 cm below the ground, often under moss, stones, or leaves, creating a network of small chambers. While their life cycle is still under study, we know that they obviously have eggs, larvae, and also naked pupae. Interestingly, the larvae can chew, unlike the adult ants, which helps them grow quickly by consuming protein. For feeding their larvae, Myrmica rubra ants hunt and scavenge dead insects. 

Some nests have been observed near those of other species, such as Formica rufa. While cohabitation seems possible, both species are aphid farmers and may occasionally compete for control of the aphid “cattle.” Myrmica rubra ants collect honeydew from aphids and share it with their sisters through a process called trophallaxis.

We discovered a nest in mid-August, and as you can see, the alate ants (both male and female) are preparing for their nuptial flights, which occur between August and September in Europe, depending on the weather. These ants will hibernate from October to March at temperatures between 5 to 8 degrees Celsius (41-46 °F)

In nature, when a Myrmica rubra ant dies, her sisters carry her body about 3 meters away from the colony and leave it there. Unlike some other species, they do not create cemeteries or organized waste deposits.

European fire ants, despite their reputation for stinging and nesting in human gardens, play a crucial role in the ecosystem. They are vital for the decomposition of organic matter and the regeneration of soils. So, the next time you encounter these ants, try to leave them undisturbed. And remember, as tempting as it might be, avoid putting your feet or fingers too close to them!