Latin: Lasius fuliginosus
The jet ant or jet-black ant is in danish called “orange ant”. The danish name is not because of the color, because the jet ant is not orange. The danish name comes from the fruit orange. Because the ant has a sweet orange scent, which scent can be enhanced when squeezing the ant so it is believed that the scent comes from within the ant.
This type of ant is widespread throughout Denmark, except West Jutland.
Appearance
The Jet ant is black in color like the common black garden ant. On the surface it is very shiny. It has a classic ant shape with a slender waist, a large head and hind and of course six legs. It is possible to see the antennae and the mouthpiece with the naked eye. The working ants are 4 and 6 mm long.
One will only see the fully grown jet ant, because they otherwise do not leave the nest.
Biology and behavior
The Jet ants can typically be found during spring until the end of autumn. If the weather is warmer, the ants are more likely to be active. Besides, they are more active during the day. A colony of jet ants will typically build their nest in a hollow tree, a tree stump, an obsolete branch, or similar trees. In rarer cases, they can build the nest directly in the woodwork on the house, which create problems for the house owner.
The jet ant feeds mainly on smaller insects, plant juices and the excrement from aphid. They create paths from their nest to the tress filled with aphids, those trails are maintained each year and they can be up to 40 meters long.
The ants create an extremely humid environment around their nest, and they will gnaw in the tree to create their nest. This is the reason why they only build nests in dead wood as live wood is too resistance towards the ants.
The nest is built with materials they have chewed like wood, plant juice and insulation material like soil. With the material they form a cardboard nest, which can be described as a stiff and black-gray fungi. The jet ant is the main source for this fungus, as they do create and maintain the conditions for the creation and development.
An ant community can exist for many years in the same place and can consist of up to 2 million workers in a colony.
Damage
The jet ant mainly damage woodwork. They do not often eat the food in the home, but their attacks on the house materials can lead to major problems. As they can chew on floorboards, which can make the floor more porous.
If you discover damp areas on the floor or other kind of woodwork, there may be jet ants in your home. The ant will try to build their nest inside the woodwork, so one will not be able to observe the nest itself. An indication for the jet ant is damp areas as well as darker wood boards.
In cases, where you can see those signs, you should check for the jet ant. Porous woodwork can become an expensive affair but also dangerous if not handled. You can possibly make a hole in the attacked areas to check if you can find any ants or nests.
Prevention and control
Besides being aware of the danger of jet ants, unfortunately, there is not much to do to prevent them. Once it has been established that there are jet ants in one’s woodwork, the ants should be chemically controlled. There are several products on the market, such as ant powder and liquid pesticide. When using those pesticide, one needs to locate the ants and nest. It can be difficult to do so if it is a new nest and it is recommended to treat the areas with pesticides or to use ant bait traps. Of course, it is important that you use the given insecticide correctly, so read and follow the instructions on the label.
"Pests in House and Home"
"Bed Bugs - Bites, Stings and Itches"
"Food Pests"
"Husets dyreliv" (Insects Around the House - Only danish)
"Skadedyr i træ" (Timber Pests - Only danish)
"Stuefluen" (Common Housefly - Only danish)