UK Environment Services | Edinburgh

Ants Nest Treatment

There are several different species of ants routinely found in the U.K which can be invasive pests. The type of treatment used to remove the ants can vary according to the species present but whatever type they are we have a treatment program that will bring about their removal.

The two species of ants most often seen in the U.K are the common black ant (Lasius niger) which is also known as the  garden ant and the red ant (Myrmica rubra) . They are both most often seen outdoors living under paving stones, rocks and in soil. In most cases they will be of no harm or concern to humans but if they enter homes or buildings; they can cause distress to occupants and contaminate food products. Ants are able to communicate effectively with other ants using pheromone trails and so one invasive ant can very quickly become hundreds of invasive ants.

Although common black ants & red ants are not particularly dirty insects, they do walk over areas that are very dirty and unhygienic. Some ants like the Pharaoh's ant are believed to carry pathogens (disease causing agents) so it is important to correctly identify the ants present and to assess the property concerned for vulnerable areas. Proofing measures and insecticide bands can be used to help ensure that ants do not gain access to your home or building.

The Most Common Ant Species

The common black ant (Lasius niger) is indigenous to the U.K and one of the very few ant species that can both survive outdoors (in the U.K) and who will also routinely enter houses.

The common black ants that are seen are almost invariably workers ants who are sterile females. These worker ants are wingless, black or dark brown in colour with the antennae & leg joints usually having a yellow tinge. In terms of size the worker ants are usually between 2-5mm in length; with the queens being much larger at 6.5-10mm and males in-between at 3.5-5mm in length. 

The male ants are only produced at certain times of the year and like the queens the male ants have wings. They are most often seen on warm days at the end of July or in August when the queens and males fly from the nest to mate with ants from other colonies. This mating ritual takes place mid-air and involves the male ants proving their physical prowess by catching the queen mid flight. Contrary to the popular myth that flying ants are only seen on one day of the year, the evidence suggests that these rituals are likely to be seen over a two week period when the weather and environmental conditions are most favourable.

After the mating has taken place the male ant quickly dies and the fertilised queen starts a new colony, which begins with a small number of worker ants. These nests are usually constructed in soil underneath rocks, trees and paving stones. Shortly after the queen begins building the new colony, she loses her wings as the reserves from her flight muscles and other parts are used as food for her first batch of larvae. Whilst only a few fertilised queens survive to set up a new colony, nests that are established can grow rapidly as the first batch of worker ants tend to the next batches of eggs and feeding the resultant larvae on insects, nectar, aphid and coccid honeydew. These nests can remain viable for many years and can merge with other nests that have been started nearby. In this case the queen of one nest will assume dominance and kill the queen from the other colony.

When ants build their nests indoors, infestations can cause problems at any time of the year and usually require skill and knowledge to eradicate. Locating the nest is of paramount importance and often several different techniques and procedures are applied simultaneously to remove the ants completely.

The red ant (Myrmica rubra) is similar in biology and nesting habit to the common black ant but there are some differences. The red ants are more carnivorous, aggressive and the species stings far more readily. The effect of these stings on humans is similar to the pain felt from stinging nettles and can be painful when multiple stings; from many different red ants, occur at the same time.

The red ant workers are on average slightly larger than the common black ant workers at 3.5-5mm in length, whilst the queens or presumptive queens are larger than the workers at 4.5-7.5mm in length. The male red ants (like many other ant species) fall somewhere between the two and are 4.5-5mm in length. Both the queens and the males have slightly different colouration to the worker ants with the queens being a brown colour, whilst the males are dark brown to black. The worker ants are a red or reddish-brown in colour but like the common black ants, they usually have a yellow-ish tinge to their antennae and leg joints.

The male red ants and the new queens usually emerge in late July and August, with the weather conditions having a significant impact on the timing of their emergence and mating. The swarms can be substantial and a nuisance but fortunately pose an insignificant health concern to humans, unless someone suffers an allergic reaction to a single or multiple stings from the mating red ants.

Ants that are only found indoors in the U.K

There are as previously mentioned other types of ants routinely found in the U.K. Most of these ants will usually be found in woodland areas and are of little concern in the pest control industry. There are however some others which exist almost exclusively indoors and can be serious pests. These are:

• Pharaoh's ant (Monomorium pharaonis)
• Argentine ants (Linepithema humile, formely called Iridomyrmex humilis)
• Roger's ant (Hypoponera punctatissima)
• Crazy ants (also called longhron crazy ants, Paratrichina longicornis)
• Big-headed ants (Pheidole megacephala)
• Ghost ants (Tapinoma melanocephalum)

The Pharaoh's ant is a tropical and sub-tropical ant species. It is found in the U.K in warm buildings such as large housing blocks, indoor gardens, food manufacturing premises, hospitals, prisons and zoos. Pharaoh's worker ants (which like all other worker ants, are all female) are yellow-ish, around 2mm in length, with male ants being around 3mm and the queens 3-4mm in length.

Pharaoh's ants are a significant pest because of their tendency to form multiple nests. This means that if one part of a building is infested, then the infestation will probably spread to other areas given time. The likelihood of the infestation spreading will usually be increased with the use of conventional insecticides and a suitable baiting program should instead be used.

Unlike the common black ants and red ants, Pharaoh's ant colonies have multiple queens which may all lay eggs. Male ants will be produced on occasion and these will mate with the new queens that will go on to replace the old queens at the end of their life cycle, which can be up to 10 months. 

The size of a Pharaoh's ant colony seems to be limited only by the food and space available with nests of over 150,000 ants (at various stages of their life cycle) having been found. Pharaoh's ants (and all the other ants) belong to the same order as wasps and bees (Hymenoptera) and follow a complete metamorphosis or life cycle. The speed of development and reproduction is dependent upon the temperature, with the optimum considered to be 30 degrees Celsius.

The Argentine ant is another tropical ant species that is only seen in warm buildings in the U.K. It is not as common as the Pharaoh's ant but its biology and habitat are very similar, with reproduction and development being temperature dependent. In cold conditions the ants can become inactive but this is temporary and activity resumes as the temperatures increase. Like the Pharaoh's ant, Argentine ant colonies contain many queens which tend to wander away from the nest, set up new colonies and live harmoniously with the original colony.

Argentine ants are slightly larger than Pharaoh's ants, with worker ants being around 2.5mm long and are brown to black in colour. The worker ants have no sting and their bite is very weak but they do have a tendency to wander from filthy areas onto food or food preparation areas.

Roger's ants are another largely tropical ant species that are found in heated buildings in the U.K. Workers are dark yellow to brown in colour, 2-3mm long, have small hairs covering their bodies and are unable to see as they have no eyes. 

Roger's ants are attracted to wet areas such as drains & toilets as they have a high requirement for moisture. They nest in small colonies and these nests are often found in damp soils or other organic materials used in plant pots.

The Roger's ant doesn't follow trails in the same way other ants do but instead forage for live prey and for the larvae or pupae of small insects. They kill this prey by injecting their powerful venom into the target. This feeding behaviour has implications for pest control technicians as it renders many poison baits ineffective and further enhances the need for correct identification.

Whilst the Roger's ant will sting humans, the sting is only serious in the case of an allergic reaction. The usual sign/symptom of being stung is a flared dermal wheel that turns into a red pimple; up to10mm across and lasts for several days.

Crazy ants are so named because of the worker ants habit of making rapid movements with frequent changes of direction. They are perhaps one the most widely distributed (globally) species of tramp ants, which is in large part due to their omnivorous diet and ability to live amongst humans. Crazy ants will eat other insects, honeydew and seeds but will also feed on meat and fruits, which can result in significant spoilage and losses to businesses and householders.

Crazy ants are small at 2-3mm in length but have long legs and antennae which gives them a more spindly appearance; when compared to other ants. These ants are usually dark brown in colour but sometimes appear slightly purple and small white hairs are usually visible under close examination.

The crazy ant is another ant that is ubiquitous in the tropics and sub-tropics but will only survive indoors in the temperate climate of the U.K. They are most often seen in large commercial or public buildings that are warm all year round and where various food sources are present.

Big headed ants are rather unsurprisingly called big headed ants because of the ants rather large head, in relation to its body size. 

The ants themselves are quite small at 2-3mm in length and are a yellow-brown to brown in colour. These ants are native to the U.S.A but a number of instances of their unwanted presence have been recorded in the U.K, inside buildings, with plants being the method of transport. 

Big headed ants have a wide and varied diet and may be most likely seen at night time when they are out foraging for food.

Ghost ants are another tropical species that are found in heated buildings in the U.K. The ghost ant workers are very small at 1.2-1.5mm in length and are varied in colour along the full length of the head & body. The head & thorax are a dark brown-black in colour but the abdomen, legs and antennae are a translucent yellow-light brown.

Ghost ants are very vast moving and form large nests which lack the structure usually seen with other common ant nests. Ghost ants are like the Pharaoh's and Argentine ants in that the established nests will have multiple queens, which go on to form sub-colonies and spread the infestation. Nests are usually found in wall cavities or heating ducts as well as in the soil of potted plants. Ghost ants eat a wide range of foods; they particularly like sweet substances and they form sporadic pheromone trails between the nest and food sources as a way of communicating the location of a food source to other worker ants.

Like the other tropical ant species the ghost ant requires warm temperatures to survive, with a minimum constant temperature of 18 degrees Celsius considered to be the lowest temperature permissible for ghost ant survival and 30+ degrees Celsius is preferred. Ghost ants also require a water source for survival and are considered to be principally a pest of multiple occupancy buildings.

In common with the Pharaoh's ant it is likely that the ghost ant carries pathogens (disease causing agents).

To get more information and remove pests from your property contact us on 0131 623 1806