How To Control Ants

Ants can certainly be annoying….. and as many have found out, ant control is not always that easy!

Their small size, large numbers and complicated social structure make controlling ants a continuous battle. Identifying the ant species present can certainly be useful, as it helps determine the potential nest locations and likely size of the nest.

However, even without identifying the species present, there are some basic principles of ant control that will allow the homeowner to get on top of almost any ant problem…..although it sometimes takes a bit of patience and a bit of persistence!

Ant Identification

Black house ant worker with larvae

What do they look like?

Ants are a typical insect with 3 body segments and six legs.
Ants are often called social insects as they have different types of ants performing different roles within the colony.
- The reproductive ants (kings and queens) tend to be the largest ants in the colony. These are the winged ants that you may see leaving the nest in large numbers to start a new one. They mate and lose their wings before starting a new nest.
- The majority of ants in the colony are the workers which carry out most of the day to day work. For some species the workers are all the same size, for others the workers can vary in size.
- Some species also have a soldier caste to help with colony defense – these tend to be larger than the normal workers.
Ants hatch from eggs into larvae and then pass through a pupal stage before turning into adults ants. Eggs, larvae and pupae are normally found in the nest, but are sometime visible when being carried by worker ants if the nest is on the move.
Generally ants are often split into black ants and brown ants, but unless you actually identify the species, it doesn’t really help with development a successful control strategy.

Types of Ants

Common species nesting in houses

Black House Ant

Colony structure: Single queen, single nest
Typical nest location: Under rocks and logs: in wall voids and roof cavities
Food preference: Sugar

Pharaoh Ant

Colony structure
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White Footed Ant

Colony structure: Multiple queen, multi-nest
Typical nest location: Primarily arboreal (in trees); in wall voids and roof cavities
Food preference: Sugar

Common species around the home and garden

Pavement Ant

Colony structure: Multiple queens, multi-nest

Nest location: Under rocks, logs and pavers

Food preference: Sugar but will eat petfood

Coast brown and (big-headed ant)

(major worker in photo)

Colony Structure: Multiple queens, multi-nest
Nest location: Under soil or pavers. Sometimes in wall voids
Food preference: Protein and oil

Argentine Ant (Queen and Worker)

(queen and worker in photo)

Colony structure: Multiple queen, multi-nest
Nest Location: Shallow nests in leaf-litter. Also under paving and sometimes in wall voids
Food preference: Sugar in the cooler months, protein in the warmer months

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Key Ant Facts

argentine ant — Argentine ants can form super colonies containing thousands of queens covering many kilometers

To get lasting control of an ant problem you will need to kill all the ants in the nest, especially the queen. If the queen survives, she can start laying eggs again and the ants will return.
However, even if you can find the nest, it’s not so easy to kill the queen because
- Many ant species have more than one queen
- Many ant species have multiple sites as part of the same colony
Some of the main pest species, such as the Argentine ant and coastal brown ant, are called invasive ants, as they cause problems all around the world. They are very successful in invading and taking over an area. One of the reasons for this success, is their multiple nest / multiple queen colony structure, sometimes allowing the colony to spread to cover many kilometres!
Even if you are successful in killing the nest causing the problem, other ants will often move into the vacated territory. This makes controlling ants a continuous battle and the best strategy is a two pronged approach; reducing ant pressure outside and preventing ants from entering the home.

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Signs Of Ant Infestation

coastal brown ant digging up dirt under pavers — Coastal brown ants are renowned for digging up dirt under pavers

Ant infestations inside the home are pretty obvious…. you see ants! Often, these may be ants nesting outside coming in looking for food and moisture. The key action is to act as soon as you see them. If you leave it a few days or weeks, they will establish your home as one of their main feeding sites and will try and keep coming back, making them more difficult to control.

If you find ants in your house and cannot find an entry point from the outside, the ants may be nesting in or under your house. They quite often nest in wall voids, roof spaces and behind cupboards. This can take a bit more detective work to find the nest and apply a treatment.

Signs of an infestation outside may include piles of dirt and sand appearing between pavers and mounds in the lawn. Although this is annoying, it can be helpful in applying a treatment as it shows where they are nesting and therefore where to apply the product.

Main Pest Season

For New Zealand the main pest season for ants are the warmer months. The queen starts her egg laying in Spring with the nests reaching maximum size in late summer and early Autumn. They can sometimes be a problem in Winter, especially if they are nesting indoors.

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Ant Prevention Tips

Petfood can be attractive to ants — Petfood left out will attract ants and other pests

Good Hygiene is Critical:

Clean away split food and dirty dishes straight away
Ensure rubbish is put in secure containers
Don’t leave petfood in bowls on the ground (or if you do, place the bowl in a large bowl of water to create a “moat” which the ants can’t cross)
Keep food in sealed containers
Seal any small entry holes in the exterior walls / around doors and windows

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Ant Control Tips

pestxpert outdoor perimeter spray — PestXpert Pro Spray Outdoor Perimeter

PestXpert Pro Spray Crawling aerosol — PestXpert Pro Spray Outdoor Perimeter

Ants are actually very easy to kill with almost any insecticide. The problem is, if you only spray the ants you see, the chances are there are many more in the nest ready to replace them! And so the ant problem will return. To gain lasting control, you need to spend some time trying to locate entry points into the home and if possible find the nest. Once you have worked out where the ants are coming from you will probably need to use a number of products to gain control.

If you can locate the nest, you will have the best chance of complete control. “Flooding” it with insecticide using a ready to use pump pack product will deliver the best results.

However, it is not easy to find the nest, and even if you do, often it can be hard to reach. Ant baits are the best way to provide lasting protection as they kill the nest. By applying bait where ants are active, they do they hard work for you, taking the bait (containing a controlled release insecticide) back to the nest, where it is fed to the rest of the colony, leading to its destruction.

Insecticide sprays (aerosol or ready to use pump pack) are useful for spraying around entry points and along surfaces where you see the ants trailing. They can also be useful for spraying internal areas which you want to keep clear of ants (such as kitchen cupboards). PestXpert Pro Spray Crawling is ideal.

An insecticide spray around the complete perimeter of the property and entry points is a key part of a control program. Make sure you treat an area 50 cm to 1 m up the wall and the same distance out from the wall across paths and flower beds. Depending on the level of exposure to sun and rain, re-treatment will need to be applied through the year.

Treatment between pavers with a liquid insecticide such as Pro-Spray Outdoor Perimeter will prevent ants making a mess of your driveway / paths.

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PestXpert Products For Ants

For outdoor treatments and injection into nests, Pro-Spray Outdoor Perimeter has the 1m spray wand for safe application.
For spot treatments and for lasting protection in cupboards the Pro-Spray Crawling aerosol with its extendable nozzle does a great job.

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FAQs about Ants

What do ants eat?

Different ant species have different food preferences – some like sugar, some like protein some like oil or fat. However, most ants will take some of each food at least some point during the year, depending on the needs to the colony. Worker ants can only eat liquid food. So if you see ants taking solid food back to the nest, it will be pre-digested by the larvae before the workers can eat it.

How long do ants live?

Why do flying ants appear?

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