Ants are one of the most common and most irritating pests you’re likely to find in your home. These tiny creatures can get into your house in any number of ways, and once they’re in, they can be notoriously hard to get rid of.
Ants spend their lives foraging for food to bring back to their nest, and so they can often be found in strange places. In kitchen cabinets, behind appliances, in bowls of pet food and you’ll even find ants in the dishwasher.
Why Ants Love Dishwashers
At first glance, a dishwasher might seem like a very inhospitable place for an ant. After all, with all that hot water sloshing around, it seems impossible that a tiny insect could survive inside a dishwasher. In reality, finding ants inside a dishwasher is quite common.
Like any living thing, ants need water. Dishwashers provide a place where they can find it. Once the dishwasher has finished its cycle, there is often some water left on the dishes or inside the machine itself, and ants will often go inside to find that water.
Also, dishwashers can have a lot of food remnants in them. All the food residue that gets washed off your dishes doesn’t always make it completely down the drain, and this can attract ants to go inside and find it.
How Do Ants Get into a Dishwasher?
By design, dishwashers seal tightly to keep water in. Ants typically get inside a dishwasher when it’s not fully closed. Maybe you opened the door slightly to let the dishes dry or maybe you didn’t close it all the way between running cycles. Either way, ants only need a tiny little gap to squeeze their way inside.
If you leave that door open even just a little bit while the dishwasher is not in use, ants can find a way inside. If you see an ant trail heading towards the dishwasher, it’s because they’ve left a scent trail to follow to this source of food or water.
Getting Rid of Ants in a Dishwasher
If the ants are inside your dishwasher, you’ll need to treat them differently. You can’t spray the inside of your dishwasher with a chemical, after all. Instead, you can address the problem like this:
Clean The Dishwasher
First up, we want to get rid of what’s attracting the ants. That means getting rid of food and water.
Get rid of the food remnants that are attracting ants. Clean out the dishwasher filter or strainer to make sure there are no food particles left inside. Not only will this make your dishwasher less attractive to ants, but it will also help it to run better.
Flush the drain with vinegar/baking soda or some commercial pipe cleaner. This will break up any food particles that are inside the drain where you can’t reach them. Vinegar and baking soda are a good ecologically friendly way to do this, but you can also get products specially designed to clean the dishwasher drain without being dangerous to your health. You could also try dumping boiling water down the drain to help flush it as well.
Scrub the dishwasher. There are lots of products on the market that can clean the inside of your dishwasher for you. But if you want to do it yourself, you can sprinkle a quarter cup of borax in the bottom of your dishwasher, then run an empty load. The borax will break down any food residue and scour the inside of the machine, cleaning it up nicely. Boric acid is also poisonous to ants, so if they eat anything contaminated with it they should die (it can even be used to make DIY ant bait).
Check for leaks. Again, you’ll probably need to remove the dishwasher kickplate to do this effectively. If your dishwasher is leaking, it may need repair. The idea is to remove any source of moisture that might make the ants think your dishwasher is a good place for them to be. Wet wood can attract carpenter ants, so don’t skip this step!
Apply Some Ant Killers
Treat for ants. If you have heavy ant activity in and around your dishwasher, you may need to place some ant bait stations underneath and around the appliance to kill the colony. This is especially true if the ants are nesting inside your home.
On the other hand, if you’re having relatively light ant activity around the dishwasher, you may be able to deal with it by an application of diatomaceous earth or Cimexa dust.
These pesticides stay effective as long as they stay dry and are perfect for applying to wall voids such as underneath and behind the dishwasher. For instance, Cimexa stays active for ten years as long as it doesn’t get wet.
Any ants that come into contact with the dust will be killed. This is a great way to kill any foraging ants before they find your dishwasher.
Keep the ants out. Once you’ve cleaned your dishwasher and got rid of the ants inside it, the best long-term solution is to do a little detective work. Look for any ant trails leading to or from your kitchen. If possible, follow the trails to see where the ants are getting into your home.
While some ant species can nest inside a building, most come from outside. If you can find where the ants are coming in, you can close it up and stop an infestation from ever happening again.
If you find an entrance, you can also treat it with an ant-killing pesticide, ideally one that has a residual effect that will either deter or kill any ants that try to cross it.
Keep the dishwasher door closed. When there are dirty dishes inside the dishwasher, it’s like a smorgasbord for ants. A properly sealed dishwasher door should make it impossible for ants to get inside. So keep the door closed tight shut to keep ants out.
Rinse your dishes. Before adding dishes to the dishwasher, make sure there are no large food particles. These can easily get stuck in the drain or strainer, where they may attract ants. Scrape plates thoroughly and consider rinsing them before they go into the dishwasher to make sure you keep as much food as possible out of the machine.
Ants Under/Behind a Dishwasher
It’s not always the inside of the dishwasher you have to protect from ants. Sometimes, you may find large numbers of ants around the appliance.
Ordinarily, ants won’t establish a colony underneath the dishwasher. Most species like odorous ants or any variety of sugar ant needs soil or sand to build their nests in. However, certain species of ant can make a home behind the dishwasher.
One of the species is the Pharaoh ant. These tiny reddish-orange bugs can build a nest in just about any void space. They do this by building the nest out of their own saliva, so they don’t need any other medium.
Another ant species that could potentially be nesting behind your dishwasher is the carpenter ant. Carpenter ants get their name from their habit of nesting inside damp wood. They chew holes in the wood to make a nest from and they need enough room for an entire ant colony so the damage can be extensive.
If your dishwasher has a leak and the wooden floor below it is wet, carpenter ants may see it as a good place to establish a colony. There are a few sure signs of carpenter ants if you’re not sure what you’re up against.
If you do have ants nesting behind your dishwasher, it’s important to understand what kind of ants they are. Carpenter ants and Pharaoh ants look very different, and they behave very differently too and they need to be treated differently.
Treating Pharaoh Ants Around Your Dishwasher
The most important thing to understand is that you should never spray Pharaoh ants with any kind of chemical. This can actually make the problem worse by causing the ants to panic. The nest will split up into multiple smaller colonies dispersed over a wide area. We also don’t recommend household chemicals bleach to use for any ant infestation.
The best way to treat Pharaoh ants is by use of ant bait. These products come in gels, granules, or bait stations. The idea is that the Pharaoh ants take the bait back to the nest and feed it to the Queen and her young without realizing it contains poison.
Baits work slowly, but they are very effective at killing ant colonies you can’t reach yourself. They also don’t cause Pharaoh ants to spread. It’s possible to make your own ant bait with borax if you’re looking for a non-pesticide solution.
Treating Carpenter Ants Around Your Dishwasher
By contrast, spraying is often the best way to deal with carpenter ants. So before you tackle an ant problem behind the dishwasher, make sure you’re certain of what type of ants you’re dealing with.
Some ant baits work on carpenter ants too. However, spraying is often a quicker and more efficient way to deal with these large ants. You may need to remove the kickplate at the bottom of the dishwasher to get access to where the ants are nesting or even pull your dishwasher out from the wall.
Liquid sprays can be helpful, but dust may be a better option. If the area under the dishwasher is dry, dust will stay active for longer and won’t cause any moisture issues. Use a duster to spread a fine coating of dust underneath the dishwasher, then make sure to put the kickplate back to keep kids and pets away from the treated area.
Black house ants are easy to treat with sprays and dusts but typically are coming in from outdoors.
Should I spray pesticides in my dishwasher?
No, never spray pesticides inside of your dishwasher.
Seeing ants inside your home can easily cause you to panic. The temptation is to want to kill the creatures as quickly as possible. But before you reach for that spray, think about the consequences.
Your dishwasher is where you put your cutlery, plates, and cooking utensils. You don’t want toxic chemicals coming anywhere near those items. Commercially-available pesticides are safe to be used in the home, but only if you use them correctly. You should never allow any pesticide to come into contact with dishes or cooking utensils.
Besides, it’s not necessary to spray the inside of your dishwasher. Most dishwashers have a self-cleaning cycle, and you can buy lots of perfectly safe cleaning products or even make your own with vinegar and baking soda.
Ants can’t establish a colony inside the dishwasher itself, only around it. Plus, even if you did spray pesticide inside the dishwasher, it would simply be washed away next time you ran a load through. So instead of spraying pesticide in the dishwasher, simply clean it using the instructions above and save the pesticide for underneath or behind the appliance.
Can ants damage my dishwasher?
It is extremely unlikely ants can damage your dishwasher. Dishwashers are mostly made of metal, making them impervious to even the strongest ants.
Ants aren’t interested in wires and pipes. The only reason ants get inside dishwashers is for water or food, not to establish a colony. If you deny them access to food and water, they’ll go elsewhere.
Having ants inside your dishwasher can certainly be upsetting but it won’t harm the machine in any way. All you need to do is clean out the dishwasher, possibly perform a pesticide treatment underneath it, and seal up any gaps or cracks where ants are coming in from outside. Then you’ll be able to clean your dishes again without having to worry about ants.
