The pharaoh ant

Latin: Monomorium pharaonis.

Pharaoh ant

Pharaoh ant

Season for Pharaoh ants

Season for Pharaoh ants

A tiny, bright yellow ant. The workers are only approximately 2 mm long. It is originally a tropical species, which has spread across the world through imports. In Northern Europe it has been known since the 1920s.
In Northern Europe, the pharaoh ant depends on heated buildings. The pharaoh ant is most often found in food stocks and businesses, but can also be troublesome in canteens, hotels, hospitals and in private households. All kinds of food may be eaten by this ant. Like the common black ant, the pharaoh ant also has appetite for jam, sugar and honey. Meat products, cheese, high-fat foods, dead insects, carrion and mouse droppings are also among the things that this ant eats. In hospitals, pharaoh ants crawl into sterile products and under the patients’ bandages. Furthermore they seek out waste, carrion and drains, so there is no doubt that the pharaoh ant can carry bacteria to food.

There are usually several queens in a pharaoh ant colony. The colonies are placed in dark cavities near heat sources. Temperatures between 27 and 30 ° C are preferred. There may be several colonies in one building. The colonies live in peaceful coexistence and have some degree of connection with each other.

Pharaoh ant seen from side

Pharaoh ant seen from side

It’s not easy to exterminate pharaoh ants. Start by examining their prevalence so that the extermination can be done throughout the whole infested area. For this purpose, one can lay out pieces of raw pig liver in plastic bags with holes in them or on tin foil. If there are pharaoh ants nearby, they will quickly be attracted to the bait. Knowing their prevalence you can begin the extermination in the outer edges of that area and systematically work your way towards the centre. The extermination itself is to take an insecticide (liquid and / or powder) and thoroughly treat the areas where the pharaoh ants live or move, and into all suspected cracks and crevices. Application of a pesticide in restricted belts in places where the ants have to pass, for example, pipe penetrations, lists, etc. is an addition to the extermination. To exterminate pharaoh ants, a youth hormone-like substance, methoprene, has also been used with success. The method is that the hormone – embedded in a mixture of the ants’ favourite foods – is laid as bait for the foraging worker ants. They bring the mixture into the colony as food for the larvae and queens. The mixture prevents larvae from developing into adult ants and queens lose the ability to lay eggs. The hormone has no effect on the adult worker ants and finished pupae of the colony. Therefore it will take a few months before all the ants have died naturally. These substances only work on insects and are therefore completely safe for humans and pets. One can then add traditional means after a period of a few weeks after the last use of hormone-bait.


The hymenoptera include ants, wasps and bees. They, like beetles, moths and flies, have complete metamorphosis. The larvae are limbless, blind and pale maggots. There are two pairs of transparent flying wings with relatively few but clear ribs. The rear wings are always smaller than the front wings. Mouth parts are arranged to either suck or bite. In most species, there is a clearly marked narrowing between the first abdomen joint and the following joints. In the rear, the females have a stinger, which for some is used for egg production and for others to sting.

The social hymenoptera, which have the most impact in foods in this country, form communities. The communities share hives, nests and colonies and are composed of males, queens and workers. The workers, which are the most numerous, are small females with undeveloped reproductive organs.


Stinging ant

Fig. 52. A stinging ant. (Wilson)

Approx. 100 million years ago, Ants (Formicidae) evolved from small solitary wasp-like ancestors. Some ants still have an actual venomous stinger like wasps. These stinging ants may attack if you accidentally sit on an anthill.

Ant spraying formic acid

Fig. 53 An ant spraying formic acid (Maschwitz)

There is usually no doubt about what the problem is. An anthill in the lawn can be eradicated by saturating the hill with a diazinon solution. The ants which occasionally turn up inside the house, the black garden ants have no stingers. They do, however, have venom glands from which they can spray the venom. The venom mainly consists of formic acid, but the black garden ants do not attack people.

The big red wood ants (Formica rufa), on the other hand, do attack humans because they attempt to bite a whole in the skin while spraying the venom.

Red wood ant colony

Fig. 54. A wood ant anthill. (Ib Andersen)

The wood ants are useful animals, which kill harmful insects, but a large anthill in the immediate vicinity of the house can be troublesome. If you want to save the wood ant colony, you can scoop the anthill into a tarpaulin and place it in a suitable location in the woods. Alternatively, you can coat the anthill {1with insect powder.

Pharaoh ant, Monomorium pharaonis is a quite small, only 2 mm long, light yellowish ant. It is originally a tropical ant, and in Denmark, it is entirely dependent on heated buildings. The Pharaoh ant can be troublesome in private households, where it seeks out foods. These tiny ants will seek out wounds, if the opportunity presents itself, and it can be affect bedridden people.

Pharaoh ants crawl under bandages and plaster casts where they can cause itching and other discomfort. They are frequently seen in hospitals. Control is difficult and usually requires professional assistance

Small black or garden ant

Small black or garden ant

Small black or garden ant

( Latin: Acanthomyops niger )

Several of the ants which otherwise live in the ground will occasionally build their nests in damp timber in the house, and these include the garden ant.

They will only start to gnaw their way into timber which has already been subject to damp and has been broken down by fungi and possibly by the attacks of beetle larvae. On this ant see also

Pharaoh ant

( Latin: Monomorium pharaonis)

This small yellowish-red ant gets its popular and specific names from the fact that it was erroneously believed to have been one of the plagues of ancient Egypt.

In fact, it came originally from the tropics and reached Europe in the early years of this century. It is completely dependent upon heated houses.

Like the native ants, this tropical species lives in colonies, but in contrast to most other ants there are sometimes several queens in each colony. When a colony has reached a certain size, some of the workers and queens leave taking with them a number of eggs and larvae.

The colonies are established in sheltered dark places, usually near a source or warmth, for these ants prefer a temperature of 27-30° C.

Once a building is infested there will soon be several so-called satellite colonies which live peace- fully together. They can be regarded as one large family, consisting sometimes of hundreds of thousands of ants.

Pharaoh ants are almost omnivorous.

They usually feed on sweet substances, but they also visit meat products, cheese, dead insects and carrion. They are sometimes found in food stores, shops, canteens and even in private houses. In most cases they do little or no damage but they can be rather annoying. In hospitals where conditions are more or less ideal for them these ants may be dangerous as possible distributors of disease. They can penetrate beneath bandages and find their way into sterile packs.

They are usually spread from place to place by the introduction of materials that contain a colony.

The jet black ant

( Latin: Acanthomyops fuliginosus)

It may also find its way into the kitchen. It makes its nest in timber and is discussed in more detail (p. 145) together with the pests of timber.

Small black or garden ant

( Latin: Acanthomyops niger)

These are the ants most commonly seen on verandas and in the house. They live in the ground, frequently under rocks or flagstones, and they will often penetrate under the house itself, particularly if it has been built directly on the ground. Ants frequently build nests in the insulation layer and from there they penetrate up into the house itself through the cracks which inevitably appear in the cement.

Garden ants can also build in mouldering timber (see p. 145). In nature, these ants search for flower nectar and for what is poetically known as honeydew but which is actually a sweet, sticky secretion produced by aphids or greenfly. When garden ants get into the house it will soon be seen that they are particularly attracted to sweet substances, such as drops of jam or scraps of pastry and cake. As soon as one ant has found such a delicacy there will soon, as though by magic, be a whole trail of them.

Naturally, of course, there is nothing magical in this. Ants cover a wide area in search of food. When one has found something sweet it can communicate the fact to others by tapping them with its antennae and also by feeding them with some of the contents of its crop.


( Latin: , Superfamily Formicoidea)

Ants can be found more or less everywhere. About 3,500 different species have been described, and these are adapted for widely varying conditions. Common to them all, however, is the fact that they are social.

The winged ants frequently seen in the middle of the summer are males and females which come out in swarms for the nuptial flight. The males die soon after mating but each of the mated queens is capable of founding a new colony. The eggs laid by the queen hatch into larvae that develop into worker ants, which fetch food, keep the colony clean and tend the eggs, larvae and pupae.