Do Coffee Grounds Kill Indoor Ants? We Asked a Pest Control Pro

If you’ve ever had an ant problem at home, you know how irritating it can be. They’re incredibly stubborn little pests and, unfortunately, it can be challenging to figure out which home hacks actually work. One non-toxic solution people often suggest is using coffee grounds to kill these little visitors—but does it work?

According to our pros, it kind of depends. The general answer is no since it’s not an effective or long-term solution for controlling an ant problem, however, there are times it might be worth a shot.

Read on to find out what they said does work, and what other things to keep in mind when you’re on a mission to rid your home of ants. 

Do Coffee Grounds Kill Ants?

David Price, an entomologist and the technical director of Mosquito Joe, says no because coffee grounds don’t have the necessary ingredients to kill the ants.

However, coffee grounds do have ingredients that can interrupt how the ants signal each other through their pheromones. As a result, this can be an effective way of repelling the ant trail.

But don’t start sprinkling your own trail yet. Unfortunately, in this case, as Price points out, it doesn’t really address the colony itself.

“As soon as the ants work out a way around the grounds, it’s no longer a solution,” Price says. 

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Certain Coffees Might Work on Some Ant Species

While coffee might not be an umbrella cure to your ant problem, there are times when it still could be worth a try. 

According to Craig Sansig, a certified entomologist and service director of Viking Pest Control, there are cases where coffee might be effective—but there are a few variables to consider. 

“There is some evidence that Arabica coffee grinds actually do offer some repellency to some ant species,” Sansig says. 

In these cases, certain species have proven reluctant to cross a barrier of coffee grounds, so it could be an effective way to stop these ants in their tracks—literally.

Coffee Can Have an Adverse Effect

On the other hand, unless you know exactly what species of ant you’re dealing with, Sansig said the coffee can have the opposite effect.

“Other studies have demonstrated that extract from Arabica coffee may act as a stimulus agent and aid in the attraction of ant workers,” Sansig says. 

Coffee Might Attract Other Pests

If you’re still considering coffee as a solution to your ant problem, Sansig gave us one more word of warning. While it might drive ants away, coffee grounds could attract other insects and could become a bigger problem than ants.

“It’s unclear whether prolonged use of coffee grounds may cause a secondary infestation of pests, namely food infecting insects like Plodia interpunctella—the Indianmeal moth,” Sansig says. 

Other Options

If you really want to avoid ant traps or chemical sprays designed specifically to kill ants, Price says you have a few other options.

“Try mixing Borax and sugar or jelly in a 1:3 ratio and inserting it into a straw and placing it [at the start of the trail],” Price recommends.  

Consider also spraying a vinegar solution at the trailing ants to disrupt them, as well as regularly cleaning all countertops, floors, and other surfaces to remove any potential food sources. You can also use ant killers to eliminate the colonies faster.

“Additionally, seal entry points from the outside at the foundation—where pipes enter, around windows, and doors,” Price says.

Price says to make sure to seal plumbing penetrations, especially in the kitchen and bathroom. Along with coffee grounds, Price also says citrus peels, chalk, and baking soda are unlikely to be effective as a long-term result. It’s important to do your research when it comes to home hacks, so you don’t create a bigger issue.