The Best Indoor Ant Spray

Buying Guide

Ants: They’re known far and wide as hard workers, industrious foragers and the bane of every picnic. But if you think they’re unwelcome at your outdoor gatherings, just wait until you see them indoors.

Once you start seeing ant scouts, it’s important to make sure they don’t report back with an “all clear.” That’s why indoor ant sprays are a decent solution for dealing with these pests on the spot — and some better sprays can give them an incentive to stay gone.

Most of us would rather not think about how ant spray works, but a little insight can help you determine which spray is right for you. Most spray is a contact poison that is absorbed through the skin. For lasting effect, you may want a spray that will stay effective on surfaces for days or more, killing or repelling any ants to come along. Then again, you may not want your pets or children to come in contact with it. That’s why the ingredients are important, both the active chemicals and the secondary chemicals that allow that spray to stay put.

Many modern ant sprays use pyrethroids like deltamethrin or commercial chemicals like imiprothrin. Pyrethroids are derived from the chrysanthemum plant while imiprothrin is synthetic. Both work by interfering with the ant’s central nervous system.

Other active ingredients like d-limonene work by disrupting the ant’s respiratory system, causing quick suffocation. D-limonene, while it may sound synthetic, is a common ingredient in orange peel extract.

If you’ve got pets or kids, you will definitely want to lean toward more natural sprays. In a lot of cases, that means you may have to sacrifice a little on-contact effectiveness, but that doesn’t mean the spray can’t be used as a deterrent. Peppermint oil is one ingredient that may smell great to most humans, but ants don’t share that opinion. Concentrated amounts of it can repel ants, so sprays that contain that ingredient can be used to make a “perimeter defense” around entryways and wall cracks — without undue danger to children.

Keep in mind that in most cases, ant baits or dust delivery systems are best for long-term pest control. These insecticides are fundamentally different since they’re not meant to kill ants on the spot. Ant baits are designed to coat ants with a slow-acting poison that they can bring back to the nest, killing the infestation at the source. If you’ve got a long-term problem, sprays are best used in tandem with baits or other methods, killing scouts in a way that’s safer for the household.

Speaking of deterrence, it can helpful to spray around door cracks and window frames outdoors, but only if you have the right spray. Most conventional ant sprays will wash away quickly with rain. make sure you’re buying a spray that’s designated for indoor/outdoor use.

How you use that ant spray can be just as important as what it contains. Most ant sprays should kill ants on contact, regardless of what type of ant you encounter. If you’re using it for perimeter defense, make sure you spray the right areas thoroughly and often, with special attention to the kitchen. Ants are resourceful critters and will often find another way in when one way is blocked, especially if there’s a ready supply of food.

Speaking of which, the best way you can prevent ant infestations is to keep your kitchen and other living spaces clear of food scraps. Sugar is a particular favorite of ants, so make sure to wipe up those spills from your coffee prep before they become an ant buffet.

Finally, you should know that there are some places that ant spray can do more harm than good. Outdoor use is generally much less effective, and spraying it directly onto ant hills might just cause the hive to spread out after killing the few ants on the surface.