Black House Ants

The black house ant (Ochetellus glaber) is a native ant species to Australia. They are usually around 5mm long and have a dark glossy appearance. Although black ants don’t carry diseases themselves, they can cross-contaminate when they march across food or your kitchen.

Bull Ants Characteristics:

Scientific Name: Ochetellus glaber
Colour: black, glossy
Legs: 6
Body: Oval thorax, two-segmented pedicel, male ants have wings
Size: Workers are approximately 2.5 - 3mm, queens can measure up to 5 mm
Antennae: 2 antennas, consisting of 12 segments
Bites or stings: Does not sting, it bites
Region: Australia

  • It takes up to 6 weeks for an egg to hatch but that period also depends on the weather. Once they hatch their bodies go through several different stages of developments before they become fully developed black ants. 


  • They hatch as larvae in the form of a white grub with a narrow end. The larvae are fed by the adult ants. 


  • When the larvae pupate the small ants look like adults, but they’re white. Sometimes they can have cocoon protecting them. 


  • When the ants are fully developed they emerge three body parts: a head, thorax and abdomen


  • Eggs that are fertilized become females, the eggs that are not fertilized become males.
  • The black house ants almost always built nests underground, under stones, in cracks and holes in the foundation, or rotten wood. 


  • The black ants are omnivorous. They form long trails seeking for sweet substances or other insects to hunt. 


  • Black house ants have defined roles in their colony. Each nest has a queen. She usually stays in the nest, mating with the fertile male ants. The worker ants are sterile females, Their role is to build the nest, take care of the larvae and scout for food and water. 


  • Winged reproductive females and males make a mass flight and mate in the air. After mating the males die and the females shed their wings and come back to the nest.

Black ants have a traditional social structure. There are three distinct castes:


The queen is the only fertile female ant. Contrary to popular belief, she has very little power over the happenings of the colony. She doesn’t “control” other ants. The queen’s only function is to reproduce. That’s her importance for the colony and why the other ants take such good care of her. Outside of that, she has very little function. The queens can live up to 30 years.


The drones are male ants whose only function is to mate with the queen, after which they die. They are winged ants and have a very short lifespan.


The workers are responsible for pretty much everything else. They are the ones that maintain the nest, find food, bring it to the nest, guard the nest, expand the nest and whatever else you can think of.

This is the reason the queen is so important. With her dead, the colony has no future.

Black ants can cause structural damage. Their digging habits can cause shifts in the sands/turf under the house. Needless to say, this is not the best thing that can happen under your home.

Aside from that, they can damage wooden foundations if it turns out you’re dealing with carpenter ants. Unlike termites, they don’t eat the wood, but dig inside of it and make their colonies there. This can be just as dangerous as the damage caused by termites, though. Immediate actions need to be undertaken. If you’re not sure what to do, you can always opt for professional ant control.

  • If the colony is old enough, the ants will be bigger since worker ants tend to increase in size throughout the generations.

  • A colony of black ants consists of around 4000 to 7000 ants. Even though this number might seem high, there have been recorded cases of colonies of up to 40 000 specimens. 

  • The queen is the biggest in size. She is a hulking colossus compared to her loyal subjects. The black ant queen comes around 9 mm, it can grow to 15mm, and can be with or without wings. The queen is glossy black and brown stripes on her bottom.

  • A black ant queen lives for about 15 years, on average. If you think that’s a long time better put that in the back of your head. There have been recorded cases where a black ant queen has made it to the impressive age of 30.

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How to get rid of black ants

Australian black ants can be particularly annoying. With the average number of workers around 4-7 thousand and a queen that can live up to 30 years, you can have a severe infestation on your hands. Don’t worry, here’s what you can do in order to deal with it:

Identify the source of the infestation

Ants don’t spontaneously show up into your home because they have nothing better to do. If you find ants in your kitchen, they’re there in order to facilitate the survival of their colony. They’re foraging for food or looking for water. Because they use chemicals as a way to mark their pathways, you can easily detect where they come from. It’s usually the last place you’d figure, like under the kitchen sink or other moist spaces. Under the door is also among the usual suspects. Whatever the source is, find it and try to seal it.

Clean the house thoroughly

Sometimes, no matter how hard you try, you can’t keep your place spotless. This is usually the time pests appear to remind you why you should. Make sure you clean the entire house top to bottom thoroughly (or hire a cleaner if you don’t feel like it or don’t have the time). This is one way to discourage future black ant visits (for a while). The thorough cleaning usually dissipates their chemical trails which makes it harder for them to get back to your house (think “Hansel and Gretel”, but if there were literally thousands of them you weren’t planning to eat them).

Spray white vinegar along the trail

The idea is white vinegar will act as a deterrent. It’s useful in some cases, not so much in other. You can still give it a try. Especially if you find where the ants are coming in.

Use cinnamon at the entry points

Cinnamon is a natural deterrent that helps with some species. It’s not a guarantee, but it’s another harmless method you can try before you get to the heavy stuff.

DIY black ant extermination methods

In case you’re the kind of person who wants to do everything on their own, here are some DIY black ant extermination methods:

Sugar and borax

This is a deadly combination. The sugar attracts the ants and the borax deals with them. Permanently (at least the ones that come into contact with it). If you’re lucky, they might even bring some to the nest and do even more damage to the colony. Note: if you have pets or kids, mix this with a bit of water. Use pieces of cotton to absorb some of the mixture and place around the path of the black ants. If you’re really lucky, they will bring the cotton to their nests.

Use baits or slow acting poisons

You’ve tried the steps above but they’ve just delayed the inevitable. Fear not - the game isn’t over, yet. The battle has just begun. The next step is to use a “Trojan horse”. Devious, yes, but also quite effective. Use a bait they will bring to the nest, which will poison the queen. Thing is, the queen is the most essential part of the colony. Without her, there is no colony. Even if you kill every single ant you encounter, more will come. But if you manage to kill the queen (or have the other ants inadvertently kill the queen), then the colony is finished and they will leave you alone.

Use natural solutions if you want to avoid pesticides

If you have a reason to avoid chemicals, there are also natural remedies you can try. One of them is boric acid. The other is diatomaceous earth freely sprinkled where ants my pass by.

Do you notice black house ants around your property?

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