Types of ants
What damage can ants cause to your property?
If ants invade and colonize the inside of your home, they can eat your food, damage the structures of your house – including the wiring – leave unpleasant smells, and bite your pets and children. Their presence will also detract from the appearance of your home.
Different types of ant killers
Some of them do so by killing the ants outright as soon as they ingest, others are designed to keep them alive just long enough for them to transmit the insecticide to the other members of the colony via the food they bring back to their brethren.
Ant killers come in lots of different forms. Some of the more common ones include sprays, liquids, gels, granule, and dust.
Liquids & Gels
Most of these products make use of a sweet solution that is designed to attract ants, before killing them. Because they don’t have absorbent properties, they are often applied with the aid of a syringe that is used to access cracks and crevices where ants may be lurking.

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Solid baits
These come in the form of granules or ‘dust’ that you spread across the lawn or other areas where ants are known to be present. They contain food which attracts the ants and which the ants carry back to the colony, infecting their brethren
Sprays
Usually contained in an aerosol can, this type of insecticide-containing ant killer can be sprayed directly onto trails of ants spotted around your home, or in the areas where ants are known to nest or otherwise hang around. Unlike liquids and gels and solid bait products, the spray naturally absorbs into the ground, and so it is able to access subterranean-dwelling pests that the former are not able to. Also, ant killer sprays are not a ‘bait’ product that relies on luring ants with food or an enticing smell. Rather they are designed so that they are odorless and non-detectable by insects; that way, the ants will have no idea they are in the presence of poison, and won’t be able to evolve defenses against it and means of bypassing the bait.
Another advantage of sprays is that the wide-ranging chemical residue will not only kill ants that come into contact with it but also form a long-lasting chemical barrier preventing future infestations. Different insecticide sprays work against different species of ants, so be sure when purchasing an ant killer spray to get one that will work against the specific type of ant that is causing you problems.
Ant killer sprays
Sprays that kill the whole ant colony
These non-repellent, slow-acting, and usually called “residual” sprays are among the best tools in a homeowner’s arsenal when it comes to combating ants. A typical residual ant killer spray will last for at least a couple of weeks (up to a couple of months) after it’s been sprayed. This means that while the spray itself will dry off in a couple of hours, the insecticide in it will remain active on the sprayed location in the form of miniature, sticky insecticide particles. These insecticides are usually harmless to mammals unless they are directly ingested or inhaled, but they are deadly to insects.
Unlike ant baits that are designed to attract the worker ants to themselves, residual ant killer sprays don’t have this effect. Instead, they are designed to be as unnoticeable as possible so that the ants can simply walk over them accidentally.
Once the ant passes over the sprayed surface, the miniature particles of the spray will stick to its legs and body. Depending on the active ingredient used it will either start poisoning the ant through its external shell (usually be disrupting its ability to absorb moisture from the air) or the ant will have to ingest the insecticide as it cleans itself later on.
In a while, the contaminated ant will return to its colony and it will either: 1) contaminate other ants by direct contact, 2) contaminate the food it was carrying and touching, 3) contaminate other insects through its now contaminated feces, 4) contaminate other ants with its corpse once it dies inside the colony.
This may all sound rather gruesome but it’s nevertheless one of the most effective solutions to most ant problems. Still, it should be noted as these sprays are not bait in and of themselves, they should be sprayed cleverly on locations that ants are likely to traverse frequently – on their ant trails, on or around their entry points into your home, etc.
Also, keep in mind that while these sprays are designed to be as safe for mammals and people as possible, it’s still very important to avoid direct contact. It’s strongly advisable to spray them in locations where kids or pets won’t accidentally touch them, where you won’t accidentally wash them off. It’s also very important to use protective gear when spraying in the form of goggles, a face mask, and rubber gloves.
Sprays that kill ants on-contact and repel them
Alternatively, on-contact ant kill sprays work in a very different way. They include the same delivery mechanism – a liquid spray that can be applied directly on ants or on their trails, and that dries off after a while. However, these sprays don’t have a residual effect and typically stop working very quickly. They also employ a much more fast-acting insecticide active ingredient which prevents them from affecting the ants inside the colony in any meaningful way.
There are also some on-contact sprays that do have residual properties and can last for quite some time. They are still considered on-contact sprays, however, because they still employ a fast-acting insecticide formula.
A fair question to ask is why would anyone use on-contact sprays over the more efficient residual killer sprays? After all, while one will kill only several worker ants, the other stands a chance at wiping out the entire colony. Well, there are still a couple of things that go in favor of on-contact sprays:
- They often act as effective repellents. Where residual sprays are designed to be unnoticeable for the ants so that they keep walking over them, on-contact sprays tend to repel a lot of the ants that see their co-workers die. This is effective if you want to keep ants off your property instead of just trying to exterminate a new colony every year after the nest of the old colony has been repopulated by a new queen.
- They don’t leave a residual insecticide for your pets or kids to accidentally touch or lick. Leaving residual insects on the kitchen window where your cat, dog or child likes to sit is a risky action to take. Instead, on-contact sprays with no residual effects will expire much sooner and leave the surface safe for people and pets.
Active ingredients explained
- Whether the insecticide is fast acting or slow acting,
- How toxic it is to humans and mammals upon direct skin contact,
- Whether there are any long-term exposure side effects even without direct skin contact.
Fast acting insecticide ingredients in on-contact kill sprays:
- Organophosphates – this is the most widely used insecticide today. It works by damaging the acetylcholinesterase enzyme in the insects’ bodies. This halts their nervous system and kills them almost on-contact.
- Pyrethrins – this natural insecticide is derived from some chrysanthemum flowers. It’s a very fast acting active ingredient with a broad spectrum of uses.
- Pyrethroids – this is a group of artificially synthesized insecticides that are similar to the naturally derived Pyrethrins. They too are fast-acting and can be used against a broad spectrum of insects.
Slow acting insecticide ingredients in residual kill sprays: - Carbamates – an organic insecticide derived from carbamic acid (NH2COOH). These are a slow-acting active ingredient that takes up to 24 hours to kill the contaminated insect.
- Bifenthrin – a slow-acting insecticide with moderate toxicity to humans and mammals upon direct contact. It has no long-term exposure effects if direct contact is avoided.
- Hydramethylnon – This slow acting and synthetically derived insecticide has a slightly toxic effect on mammals upon direct contact. It is also listed in the California Proposition 65 as a carcinogenic.
Ant killer sprays buying guide
Be careful!
The insecticides contained in ant killer sprays can cause serious harm to your pets and children if you do no take the proper care.
Some insecticides are safer than others, a few of them are actually advertised as child and pet safe, so choose wisely here if you have little ones scampering around at your home.
Ants may seem harmless enough creatures – compared to termites, say – but they can still cause you a lot of hassles. If ants have already made great inroads upon your territory, then decisive action is required, and there are few better options than a good ant killer spray.
So, to summarize, which are the factors to consider when buying an ant killer spray:
- Do you need an on-contact ant killer spray or one with a residual effect? The former act mostly as repellents while the latter gives you a fighting chance at wiping out the entire ant colony. While the latter is often preferred as it is more decisive, simply repelling the ant invasion with an on-contact kill spray has its merits from time to time.
- Do you need to be wary about the toxicity of the spray? If you have pets or children it is of the utmost importance that you are careful with what you apply to your home. Many insecticides have devastating effects on mammal biology when directly touched, consumed or inhaled. Additionally, some insecticides are harmful even without such direct contact but simply due to prolonged aerial exposure. Knowing what you buy, what you’re going to use it for, and what you’ll need to look out for are all essential considerations here.
- Does the spray you are about to buy has a noticeable odor? Some sprays are completely odorless while others have a significant smell. If you are about to spray them in an inhabitable area (such as a garage or a crawl space) the smell might not be a problem but it could be significant in the kitchen.
- Does the residual spray stain certain fabrics and surfaces? Some residual insecticides are so strong that they can damage the surface they are sprayed upon. This is rare with ant killer sprays but it’s still to be looked out for.
- What is the price/quantity/residual longevity of the spray? Don’t just look at the flat price of the product but also consider how many applications it will be enough for, as well as how long each application will last (in the case of a residual spray). This correlation will give you a more accurate idea as to how much you’ll be paying compared to other products.
- What is the brand of each product? Branding is not a sole factor that should drive your purchase as there are a lot of famous brands that sell sub-par products and a lot of unknown brands that offer great quality. Still, if you are at a loss as to what to do, keeping the brand in consideration can still point you in a good direction. Here are some of the brands we’d recommend: Wondercide, EcoRaider, Ortho, Cutter, Cedarcide, Eradicator, Orange Guard, Hot Shot, Spectracide, and Eco-Defense.