Caring for Myrmica rubra
Myrmica rubra, or the European Fire Ant, is a semi-difficult species to keep. They form large colonies with multiple queens and require both a high intake of insects and a high level of humidity.
What does Myrmica rubra need?
Small colonies are best kept in test tubes with access to some sort of foraging area. Larger colonies can be housed in ytong nests (bonus: since the ytong is white, the ants will be easy to spot!) or in a dirt setup for them to dig through. Myrmica is good at nesting in many different environments. The difficulty when choosing a formicarium is to be able to keep the nest moist with the correct levels of humidity.
The temperature in the nest: 21-24°C. Room temperature is good for Myrmica rubra colonies. Since red ants, like most ants, enjoy heat a heat lamp or heat mat might be a good idea. But be careful not to burn your ants to death. Somewhere around 25°C a couple of hours a day maybe? But keep in mind the humidity levels must be maintained so please apply moisture when heating the formicarium/nest.
Tip! Heat only one part of your setup. This way the ants can choose themselves if they want to be warm or not.
Moisture level in the nest: 50-70%. Some Antkeepers prefer a higher level of humidity. Experiment with what works best for your colony, but keep an eye on the ants so they don’t die.
If you find your formicarium going dry too quickly you may have a material problem. Make sure your setup has enough things to bind the moist (dirt/sand etc.). Try putting a piece of wood in there or something to achieve the right conditions.
Sugar- or/and honey water. Fruits such as apples and pears can be very popular. Experiment with different sorts of sugar mixtures to find out what your colony likes the best. The queen and larvae need protein and this species loves protein. Provide this in the form of insects (fruit flies, mealworms, crickets, bees, wasps, beetles etc.) meat (free of poison or spices), eggs or something else containing protein. Be aware of what you feed your ants. Avoid poisonous things, such as the peel of sprayed fruit. If you’re catching your own insects, remember there is a risk they are infected with disease or parasites. So be careful and boil your insects before feeding them to your ants.
If you want to feed your ants live food, make sure the food is immobilized before feeding. Unless you have a huge colony your ants will probably suffer casualties while trying to kill their prey.
Myrmica rubra hibernate. This means they are used to not being active during the winter months. They go into their nest and huddles together, waiting for spring to come. To remain healthy, Myrmica rubra requires proper hibernation. Colonies keep food and brood in the nest during hibernation, unlike many other ant species.
You can easily hibernate your ants in most spaces with temperatures below 5-10°C. Some even use their refrigerator to hibernate their ants. Just be careful exposing your ants to too cold temperatures.
The hibernation should be synced with the seasons. When ants usually withdraws from the surface in nature you should probably hibernate your colony.
The months of hibernation usually stretches from October to around March.
More information on Myrmica rubra
Worker: Length: 4,0-5,5 millimeters. Orange-brown throughout the body with darker pigmentation on both head and abdomen.
Queen: Length: 5,5-6 millimeters. Very similar to the worker caste but a little bit bigger with darker shades. Can easily be mistaken for a worker but still has a larger thorax and abdomen fitting of an ant queen. It is somewhat unknown, but the species actually have two kinds of queens. The one a bit larger than the workers, and one the same size as them. These smaller queens are called microrubras.
Male: Length: Length: 4-6 millimeters. Very dark, to the naked eye they have almost black bodies. (1)
Myrmica rubra is found from the British isles all the way to the eastern parts of Siberia. The species is distributed throughout Scandinavia except for in the high mountain areas and the most northerns parts of the mainland. The species has also been found in North America (East coast). (2)
Number of Queens
Polygyne. Colonies only have many queens.
Nests in dirt/sand and prefer to situate themselves under stones or other objects that generates heat. The species is also found in tussocks, directly in the ground, lawns, pavements or close to plants.
Getting Hold of a Queen
Queens with colonies are easily found in ant shops around the globe. Instead of buying a queen, since it is illegal in some areas, you can catch one yourself. Myrmica rubra likes nesting under stones so it is a good idea to gently flip rocks to see if there is a queen in sight for you to capture.
Tip! Try flipping stones to find queens and workers enjoying the warm upper floors of the nest!
The nuptial flights take place somewhere from the end of July until late summer. (3) The Myrmica rubra flies in great numbers, something that from time to time is reported on in the media. Please observe that the species sometimes also mate outside of their nests, so not all queens actually fly away. This is one safe way of founding satellite nests.
Myrmica rubra might be most known for their hurtful bite. The species is fast and aggressive and do not hesitate to emerge from the nest to fight intruders. Including their keeper.
1. Per Douwes, Johan Abenius, Björn Cederberg, Urban Wahlstedt (2012) Nationalnyckeln “Steklar: Myror-getingar. Hymenoptera: Formicidae-Vespidae” p. 83 (Swedish)
2. AntWiki – Myrmica rubra
3. AntWiki – Myrmica rubra