Coffee may attract or repel ants. Scientific research has been inconclusive. If you sprinkle coffee over a chain of ants, it will disorient them, but not detract them. But, ants also appear to be attracted to coffee residue left around the house.
This study shows that ants are attracted to coffee water. The study compared distilled water to coffee water to show that ants will gravitate to the coffee water more than the distilled water. The study was conducted across a range of different species and all were attracted to the coffee.
By contrast, this study found that coffee placed in ant baits is a repellent to ants and can even cause some deaths in ants, although that data was not significant enough to be conclusive.
Both scientific studies we looked at highlighted that there are much more effective ant repellents than coffee.
Therefore, in general, it’s not advisable to use coffee grounds to keep ants away from your house, and it’s better to keep your house clean of coffee residue. If there’s any small deterrent impact, this effect is not long-lasting, and the ants may return to collect the coffee residue later.
What’s a Better Ant Repellent?
You’re better off keeping a clean home and using store-bought repellents than coffee as an ant deterrent.
The best deterrent is to make sure there’s nothing in your home, like sugars or open food containers, that will attract the ants in the first place. If there is no incentive for an ant to enter your home, they will look elsewhere for food.
If you have a current infestation, you can contact a pest control agency or use a proper store-bought ant repellent containing Borax. Follow the instructions on the box.
Why Do People use Coffee Grounds as an Ant Deterrent?
Coffee grounds can temporarily disorient ants in some circumstances, but it is temporary and only when it confuses ants by overpowering the scents the ants were originally following.
Ants don’t have a nose. They use their antennae to pick up any trails of chemical cues left by their fellow ants. The strong scent of the coffee may prevent the ants from smelling other smells, such as their fellow ants, and get confused.
Hence the ability to detect scent plays a significant role in their daily lives.
The strong scent of the coffee grounds is a result of multiple components present in the beans themselves. Each of those components, when brewed, produces its characteristic scent that ultimately creates a cocktail of an ultra-strong aromas that come off the coffee grounds.
The majority of ants will get disoriented by this strong smell if it interferes with the chemical cues they have been following. However, this is only temporary.
What Does Caffeine do to Ants?
Coffee is rich in caffeine which is known to have a strong pesticidal property.
Ants often, after coming in contact with caffeine sources (especially with baits containing caffeine along with other chemical components) perform grooming activities to get rid of the substances that can put their lives in danger.
They clean their own as well as the body parts of the other ants with their mouthparts.
During these processes, there lies a high chance of accidental ingestion of the caffeine components by these ants which further increases their disorientation and illness.
Some research found that the varieties of ants which perform allogrooming (caregiving each other through physical contact) more frequently than other varieties are more prone to the adverse effects of caffeine toxicity.
However, the effects of caffeine on the ants depend a lot on the kind of coffee that is being used and its concentration.
Related Article: How Do Ants Find Food?
Why are Some Ants Attracted Coffee Makers?
Some ants are believed to be attracted to the scent of coffee owing to the presence of a component called undecane.
The undecane is a volatile hydrocarbon that can cause major excitement in certain species of ants and encourages them to move rapidly. As undecane is highly volatile in nature, it can easily diffuse in the air and hence end up attracting the ants.
Coffea arabica is the most common types of coffee in the world. This type of coffee does contain undecane, and therefore it can end up attracting certain ant species towards itself.
Hence, the scent of the coffee grounds that lingers in the coffee maker ends up attracting the ants.
The wide range of cracks and openings in the machine further allows them to enter into the coffee maker with ease. Furthermore, the warmth and moisture inside the coffee maker act as the perfect ground for the ant infestation.
Related Article: Do Ants Like Honey?
How to Clean Coffee Makers Infested with Ants
Note that it’s best to clean coffee makers according to the instructions of the manufacturer. Each machine has different needs. Below is a general guide that may not be suitable for your specific make and model.
Here are some of the steps you can take to clean your coffee maker infested with ants and other insects:
- Unplug the coffee maker from power sources.
- Place all parts that can get wet under warm running water (remembering not to wet electrical components).
- Give those parts a thorough overall wash with water and soap suds to remove the ants in one go.
- Disassemble the machine into smaller parts and use detergent and water to cleanse each part that can be exposed to water.
- Parts that cannot be exposed to water can be wiped with a cloth, remembering to avoid touching parts that are electrically charged.
- Reassemble the machine and pour a mixture of equal proportions of water and vinegar into the reservoir. Let it run for a cycle.
- Next, drain the mixture and fill it up with water. Now again run it for a single cycle. This way you will be getting rid of all the traces of ants as well as vinegar in the coffee machine.
If possible wash your coffee maker with water and detergent after every use or at least a few times every week to remove residues that may attract ants.
Related Article: Are Ants Attracted to Salt?
How to Keep Ants Away from Coffee Beans
Make sure your kitchen is not being invaded by ants. If they move around freely in the kitchen, no matter where you keep your coffee, they will end up finding it eventually.
The kitchen provides the ants with the ideal place to find food scraps. It has ample amount of food sources, moisture, closed shelves, etc. So, kitchen ant infestations are very common.
Keep open food packets and food scraps to a minimum. Place all food in sealed containers to prevent the spread of smells.
Similarly, keep the coffee in airtight containers and keep them in high-up shelves.
You could also use store-bout ant baits in the kitchen. Follow the instructions of the ant baits exactly. Some may disallow use of those baits in kitchens. Borax and diatomaceous earth work well in keeping ants at bay.
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Unfortunately, the data on whether coffee repels or attracts ants is inconclusive, with studies showing conflicting results. What is clear, however, is that there are superior ant repellents out there, meaning using coffee to repel ants is not advisable, and keeping a clean kitchen with as little coffee residue as possible is advisable to prevent ant infestations.
So, make sure you take extra care while storing coffee in the kitchen especially if you already have ant issues in your home.
As for using coffee grounds to prevent ant issues in the house, you will be better off using commercial ant baits as they will have a longer-lasting effect, unlike the coffee grounds.
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