Pest Controller and Consumer Guide
These damn ants. Where did they come from?! There is little doubt that these words were part of our vocabulary since the beginning of time. When it comes to ants, we tend to have mixed feelings for them. While we tend to love them and admire them for their hard work, social skills and their ability to adapt the environment to themselves, we pretty much hate them when we find them inside our homes or workplaces.
They can also be a nuisance in agriculture when they attack crop seed beds or when they transport aphids and coccids that are harmful to our crops and orchards. We watch them with admiration on how they do their work, remove dead animals and insects from the environment and literally performing cleaning up. Of course, this is when they are outside of our living areas. Things change rapidly when they cross the borders of our homes and we spare no effort in trying to get rid of them. No matter how you feel about ants, much time has been spent on studying their behaviour as well as studying ways how to get rid of them.
Have an expert answer your question about ants
Ants are social insects that belong to the order Hymenoptera (Superfamily Formicoidea, Family Formicidae) together with bees and wasps. Most species in these groups are known as social insects as they tend to live in colonies and have the highest levels of communication. Communication is achieved through odour which plays a vital part in territorial and sex behaviour, especially when it comes to bees. Ants use pheromones to leave trails which other ants can then follow. To our bad luck, most ant, bees and wasp species have a powerful sting which can hurt pretty bad. However, they are not all bad. Most Hymenoptera species, especially the honey bee (Apis Mellifera), have an important role in pollinating plants. Every ant species is a social species and has a number of different castes: fertile females which are often called queens, males, and sterile female workers. Workers which are all sterile females can be divided in soldier castes with major and minor types of soldiers. Today, there are around 15 thousand known ant species and subspecies in the world from which a tenth of those can be found in Australia. Ants are found in every Australian state and territory and most of them can be found in bushlands and rainforests. Ants are typically black, brown, red and yellow colour and can vary in length from 1 to 30 mm. Their typical appearance is with their waist located between their thorax and abdomen. They have a large metapleural gland opening on each side of the methatorax. Ants have antennae and mandibulate mouthparts and some of them can have a sting at the tip of their abdomens. They undergo a complete metamorphosis starting from the moment the queen lays the first eggs in a small underground chamber. From these white eggs, larvae hatch and after pupation, the adult castes emerge. Female and males are typically produced at a fixed time of the year but these depend from species to species. When both the males and females are winged, there might occur a mass nuptial mating flight. After the mating has taken place, males die and females get rid of their wings and find a suitable location where they will start a new colony. These flying ants have a high mortality rate which is basically very convenient for us because, otherwise, we would be neck deep in ants.
Pests and ants
The majority of ant species are not considered as pests but only some native and introduced ant species are a cause for concern. Some ants make their nests in decaying wood and are suspected to cause destruction when in fact they will only infest already decaying wood.
Most ants come from the outside of households but they can commonly find nests in places such as roof voids, wall cavities, inside window screens and behind bathroom tiles. Basically, ants like the same places as cockroaches so the control methods are very similar. Because of their nesting habits, ants often leave piles of gritty matter on the horizontal surfaces or around doors and window frames. If you inspect these piles up close, they often contain dead ants which have been removed from their nests.
No matter how hard you clean the piles, they will continue to reappear as long as there are ants living near. This is not big of a problem but it tends to get bigger as ants make their way inside pantries or inside food containers. Luckily for us, they are not considered to be dangerous to human health but very rare Pharaoh´s ants which are very common to hospital areas can sometimes carry diseases.
Biology and identification
Pest ants are usually divided in two ways: colour and size, for example, small brown or black ants or by food preference such as protein food eaters or sugar eaters. Whatever way you choose to categorise them; it is essential to identify them correctly before using ant baits to control them.
The most common species of small black ants are:
- White-footed black house ants or, as they are often called, black household ants in Victoria (Technomyrmex albipes) are an ant species which will nest both on the inside and on the outside. They are 2.5 mm – 3.0mm in size and have a black colour with pale amber tarsi. Their diet consists of almost everything but they prefer sugary foods.
- The Black house ant (Ochetellus glaber) is an ant species which normally makes their nests in the ground or in decaying wood. These ants will also make their nests in roof voids and similar building cavities. Their colour is shiny black and their size is typically 2.0-3.0 mm. Their diet is mostly sweet food.
The most common species of small brown pest ants found in Australia are:
- Coastal brown ants (Pheidole megacephala) is an ant species usually found in buildings and under paths or in rockeries, throwing out piles of soil and debris. They are approximately 1.5-3.0 mm in length and have light brown or brown colour. Their diet consists mostly of proteins and fats. Coastal brown ants have minor and major soldier castes. Major soldier castes can be noticed by having a relatively larger head.
- Brown house ants (Doleromyrma darwiniana) are ants that have similar nesting habits as coastal brown ants. They are brown in colour and can grow from 2.0 mm to 3.0 mm in size. They release a distinct odour when crushed because of formic acid that they contain. Their diet consists mostly of high protein food.
- Pharaoh’s ants (Monomorium pharaonis) is a very rare ant species in Australia but is very common in Europe and USA. These ants often build their nests inside buildings as they prefer warm locations such as heating ducts. Their colonies are very large and can have multiple queens which tend to leave their nests and start new colonies at the first sign of trouble such as insecticides. Pharaoh´s ants are usually 1.5 mm-2.0 mm in size, have yellow brown or dark brown colour. Their diet consists of protein food, fatty and sweet food.
- Argentine ants (Linepithema humile) is an ant species which first arrived from South America. They are known as a very serious pest and were the target of many eradication campaigns which started in the 1950’s. These ants nest in exposed soil or hidden by plants or logs. They are 1.5 mm -3.0 mm in size and have light brown or brown colour. They can be very aggressive and can drive out other ants and other animals from their living/nesting areas. Their diet is very broad and contains sweet foods, meat, insects and seeds.
- Odorous ants (Tapinoma minutum) are ants who make their nests inside buildings and in wall voids. They are 2.0 mm -3.0 mm in size and have a brown or dark brown colour. Their diet consists of sweet foods, meat and household scraps.
- Singapore ants (Monomorium destructor) are ants which have similar nesting habits as coastal brown ants. However, they have been found nesting in electrical switch boxes as they can bite through plastic and rubber. They are 2.0 mm -3.0 mm in size and have light brown colour with a darker posterior abdomen. They have a powerful bite and sting. Their diet consists of both sweet and animal foods.
History of pest management
In the old days, ant control measures were really unsophisticated. The pest controller would arrive at the location, unroll his long hose and deluge the front and backyard with approximately 60 litres of insecticide, typically organochlorine. This blanket spray, as often called, would cover all gardens, lawns, pathways and the base of the house. Roof voids would have been covered with a synthetic pyrethroid powder and sometimes with space sprays with Dichlorvos. Was this effective? Well, whatever you think, this method often required a call-back as ants were still showing everywhere.
So, why was this method ineffective? Mostly because there was no real effort in trying to locate the nests. With this approach, insecticide would kill mostly workers but would leave the larvae and pupae unharmed, leaving them to emerge as adults. The emulsion of the insecticide would be absorbed into the surface and this would prevent it to be picked up by the insects. However, this was the only and most used method which no one questioned, except for those who still had problems with ants. Later on, insecticides were applied in a grid pattern to reduce the quantity used. Organochlorines were still not available at this time and organophosphates such as chlorpyrifos were used. These were highly toxic and had a strong smell. More importantly, they were much more expensive. The breakthrough arrived with the introduction of ant baits which were available as solids, liquids and viscous gels.
What will your pest controller do?
So, how exactly can we get rid of the ants? First thing is to undertake a thorough inspection which should start with a conversation with the clients. Their children are a good source of information as they can spend more time looking at ant activities. If you have access to a floor plan, mark all the areas where the ants are tracking. This can help you to determine the location of the nest and can help you when planning where to place your baits. If the tenants cannot be of assistance, try looking in the following places:
- Kitchens – benchtops, skirting boards, window sills, behind and inside cupboards, back side of the refrigerator where the motor is located, behind kitchen taps and wall tiles and under the sink.
- All interior areas – skirting boards, carpet edges, window sills, power points (watch out for of electricity), electrical cables, taps and tiles. Look for piles of grit, sand and dead ants as these usually form directly near the ant activity;
- Exterior areas – ants can be anywhere as they can be trailing near fence rails, paths, in the lawn or in the garden. Some species can be more active during the night. Following an ant trail that seems to disappear suddenly, you may find them appearing outside near the point of disappearance. If this proves to be unsuccessful, it probably means that they are nesting inside a wall or roof voids. Since ants are social insects, they need to have a nest which is their center of operations. Some ant species nest in decaying wood and soil, while some nest inside dwellings in a wide range of locations. Black ants have been found nesting in vehicles having made their nests in the First Aid kit in a glove box and inside the wing mirror of a pest control van! If you can find the nest, it will make your job a lot easier as you can deal with it directly. If not, you will have to use sprays, dusts and baits. These will take longer but if you use them as they should be used, they will still have a good effect. When using ant baits, it is imperative that you identify the ant species so you can use the correct bait.
Ant control and the queen
Ant colonies which have only one queen such as Camponotus ssp can be dealt with easily. Ant species which have multiple queens and nests such as Argentine ants, Odorous house ants and Pharaoh’s ants can present a much more difficult task. This is why identifying a species is of utmost importance. Many pest controllers do not bother identifying the ant species and simply class them as black or brown. In some cases, Pharaoh´s ants have been identified as coastal brown ants and treated with a synthetic pyrethroid. This resulted in the disturbance in the colony which led to multiple queens leaving the colony and nesting at other places. This is why proper identification of ant species is very important and should be done before doing anything else.
Baits, Sprays and others Formulas
With a vast variety of specific ant baits, we almost managed to solve your ant problems in houses and our backyards. Ant granules were great in controlling some ant species to stay outside. The majority of insecticide producers advise that a two-way approach using both baits and sprays should be used to achieve best results. All of these producers also have complete instructions on using their products and the instructions and labels should be read before using the insecticide. Some of the basic rules for using baits are as follows:
- Hopefully, bait should be consumed within 1 to 2 days because their palatability and moisture is at its highest levels. Ants should die within 3 days.
- Correctly identifying the ants will allow you to choose the correct bait and can help you to even find their nest and feeding sites.
- Try to find the ant trails because if you place the bait where there are no ants, you have wasted the bait.
- Select the correct bait formula. Some ants prefer sweets while others prefer protein foods. Sometimes, the same ant species can switch diet based on the season or a range of other conditions. Because of this, you should have a range of baits at hand.
Using ant baits is very similar to using rodent baits. Some key rules to using it are:
- Put the bait to ant trails as close as possible because they are usually close to feeding or nesting sites.
- Put ant bait in adequate amount so you can be sure that they will continue to feed until your next visit.
- Avoid food competition by removing all other available food and liquids.
- Do not place gel baits near heat sources because gel can become liquefied and ineffective due to moisture loss. Avoid placing them on porous surfaces as they can increase water loss.
- Some kinds of baits lose their potency very quickly when exposed to sunlight so make sure that you know what kinds are sensitive to sunlight so you can replace them accordingly.
- Some kinds of granulated baits will lose their effectiveness in three months after opening so make sure to write on the package the date when you opened it.
- Most common advice is that bait should not be placed on surfaces that have been or will be treated with powder insecticides or liquid insecticides.
Pest controllers often say that applying two different formulations is nothing but waste of money and this can be a good rule to live by. There is a high chance that you will be able to solve your ant problem without the use of insecticidal sprays and dusts but all producers of ant baits recommend that baits are supplemented by using such formulations when dealing with free standing buildings. These insecticides will prevent any future ant activity in the interior. Some basic rules of using insecticide sprays are as follows:
- Non-repellent formulations are often superior to repellent formulations such as synthetic pyrethroids. This is because the ants will go through the non-repellent insecticide unknowingly. Some kinds of non-repellent actives and formulations are Bendiocarb, Fipronil, Indoxacarb and Chlorfenapyr.
- The sprays need to be applied to the base of walls, fences and garden beds.
- Sprays should be re-applied after the rain.
- Insecticidal dusts need to be applied to roof voids as well.
Ants are in most cases considered as a big problem when they show themselves in your home or office. If they keep themselves to the outer world such as your back yard, they are often left alone. In general, ants are little insects that inspire people all over the world for being such hard workers. Ant control used to be really hard and it became easier after the discovery of effective gel and liquid baits. They are very useful insects with an important function in the environment. They clean the environment and aerate the soil. This is why ants should not be killed unless there is a really good reason to do so.