More than a few people have surprised by a cockroach in their dishwasher as they opened it up. Not only is this a gross and surprising find, but most people find themselves wondering how these little critters even found their way into the dishwasher.
Once you know a little more about cockroaches, it should come as no surprise that the dishwasher is the ultimate cockroach attractant.
So, how do you take action to get rid of cockroaches in your dishwasher? In this article, we discuss the biology of the cockroach, why they are attracted to the dishwasher, and the actions you can take to ensure that you will no longer find any unpleasant surprises in the device that is supposed to be keeping your kitchen clean!
Why Do Roaches Love the Dishwasher?
Roaches have a reputation for being “indestructible” – as if they are the ultimate pest that is impossible to eradicate. In reality, cockroaches have the same needs as every other animal.
They need food, water, and shelter to survive and thrive. Unfortunately, a dishwasher can readily provide all three of these basic needs.
Dirty dishes provide an ample food source for cockroaches. Even if you are rinsing your plates before you put them in the dishwasher, there is likely still enough food left on the dishes to sustain several cockroaches.
Cockroaches can eat about everything, so even a thin layer of sauce or some tiny chunks of food can provide a decent meal for a cockroach.
Any food bits that make it into the dishwasher also need to be washed away, which doesn’t always happen. It’s possible for food to not make it to the drain, and be stuck within the drain tube itself where cockroaches can still access it.
There is more than enough water in a dishwasher for them to survive. Water gets left on clean dishes, in the drain, and small drops of water on the inner lining of the device from the high humidity.
If your dishwasher is leaking at all at the back of the unit or underneath it, that’s another excellent source of water for cockroaches to depend on.
As for shelter, cockroaches typically won’t be living in the dishwashing compartment (the area where you load your dishes and utensils). If you find one in there, it’s likely just because the cockroach was temporarily getting food or water.
However, underneath and behind a dishwasher is a perfect place for a cockroach harborage to be. Cockroaches love dark, damp, confined places.
Some people have also found cockroaches living inside of the housing of their dishwasher, for example inside the dishwasher door. We’ll get more into that later.
How Do Cockroaches Get into a Dishwasher?
While cockroaches may not be able to survive in the main wash chamber of the appliance while it is running due to the heat, your dishwasher may have design flaws, loose seals, and tiny gaps that allow cockroaches to get inside of the dishwasher.
Cockroaches can also get into your dishwasher if you leave the door ajar and not completely shut while it’s not running, as most all of us do!
Most cockroach species have an extremely flat body. This means that they are able to squeeze themselves through some very narrow cracks. Even brand new machines can have gaps and loose seals that can allow cockroaches to slip inside the outer shell.
Cockroaches are Also Under the Dishwasher
Another thing to remember is even if you’re seeing cockroaches in your dishwasher it doesn’t mean they’re actually living inside of it.
The most likely scenario is they’re living UNDER the dishwasher.
Most dishwashers have a large void underneath them where the plumbing runs. This makes a perfect harborage for cockroaches because it is moist, warm, and dark.
Just making sure you close your dishwasher door isn’t enough to fight the cockroaches because at this point they’ll find other sources of food and water in your home regardless.
At this point, you may be thinking that the best way to get rid of the roaches is to get rid of your dishwasher! Don’t fret… there are some very easy methods of getting rid of cockroaches, even in the dishwasher!
Eliminate Cockroaches in the Dishwasher
If you use the following three-pronged approach, a cockroach infestation in your dishwasher can be managed by the average homeowner. The key is to be vigilant with each step, don’t cut any corners, and follow up with the treatments on a regular basis:
1. Traps and Baits
The first step is to kill the adult cockroaches that are present. They will have laid many eggs in their harborage and around your kitchen, but we will deal with these next.
Cockroach traps and gel baits are cheap and very effective. They’re essential to any cockroach infestation removal strategy, regardless of where they are in your home.
Traps typically use a sticky glue that roaches get caught in. Sticky traps basically look like a thin sheet of cardboard, with a very sticky adhesive on one side. Most of the time these can be slipped underneath a dishwasher or at least at the base of it to catch cockroaches that come and go.
Sticky traps also help monitor an ongoing cockroach infestation to see what kind of progress you’re making.
Baits are basically food that cockroaches find attractive laced with powerful insecticides that cause the cockroach’s nervous system to malfunction – leading to death.
Baits are extremely effective because cockroaches will share food, eat each others vomit and feces, and even eat other dead cockroaches! One cockroach that takes the bait will pass it on to several others.
You can bait around your dishwasher, in the cabinet under your kitchen sink, and anywhere else near your dishwasher can reasonably access.
Be sure to check the cockroach bait every day or two, and if it’s gone put more in the same spot. If cockroaches aren’t taking the bait after 3 days, just wipe it up and try baiting elsewhere. Bait gets stale and cockroaches prefer fresh bait.
2. Check Your Dishwasher Seals/Leaks
A well-maintained dishwasher is less likely to attract new roaches than a damaged or malfunctioning dishwasher. Most dishwashers have a small panel on the front, just below the door. Remove this panel, get a flashlight, and check the space under the appliance for leaks, roaches, or any signs of roaches (like feces, food scraps, or eggs).
You should also check all the seals on your dishwasher. Typically, dishwashers only have two areas where roaches can reasonably access the inside. The main seal on the door can become weak and damaged over time, or may have a design-flaw that stops the door from fully sealing to the outside. Secondarily, some dishwasher drain lines do seal completely with the drain they dump into. Small cockroaches can sometimes make their way into the unit via this drain tube.
3. Clean up, then add some Dust!
Roaches find and join harborages based on smell. All the nasty feces, dirt, food scraps, and cockroach smells underneath your dishwasher are likely attracting more roaches.
The best place to start is to vacuum out the mess. If you can, spray some bleach and wipe down the surfaces under and around the dishwasher. This should eliminate the attractive smells the cockroaches have created.
Next up, get some Insecticidal Dust. There are many types on the market, from Diatomaceous Earth to dust products that contain synthetic insecticides. These products generally work by destroying cockroach exoskeletons (and those of other pests), which eventually leads to them drying out and dying.
Using a billow duster you can shoot some dust under and behind your dishwasher which will kill cockroaches that cross it’s path for months and years if left undisturbed.
Should I Spray Raid or Bug Bomb my Dishwasher?
A common question people have is about spraying Raid (or other insecticide) inside their dishwasher, or even using a bug bomb/fogger in their dishwasher.
The answer – No! Raid and other toxic insecticides are not made for use directly on surfaces that use for food preparation. If you put these toxic substances into your dishwasher, they will undoubtedly get onto your plates, silverware, and other items. They might look “clean,” but they will definitely have a chemical residue on them.
Remember, cockroaches typically don’t live inside your actual dishwasher, so you don’t need to treat that area with pesticides.
In general, if you follow the advice above, you should be able to completely eliminate the cockroach infestation without using any toxins in your actual dishwasher. There is absolutely no reason to contaminate your dishwasher with insecticides.