Bugs in your dishwasher are more common than you’d expect, and the usual culprits are cockroaches, ants, silverfish, and carpet beetles. Your dishwasher offers exactly what these pests need: warmth, moisture, food residue, and dark, protected hiding spots. The good news is that getting rid of them is straightforward once you understand what’s drawing them in and where they’re hiding.
Why Bugs Love Your Dishwasher
A dishwasher is essentially a pest buffet. Even tiny crumbs or liquid residue left on dirty dishes provide enough food to attract insects. The warm, humid environment inside the machine, especially after a cycle finishes, makes it even more appealing. If your dishwasher sits loaded with dirty dishes waiting to run, or if a finished cycle sits overnight without being opened, you’re creating ideal conditions for pests to move in.
The area around and beneath the dishwasher matters just as much as the inside. Spilled food that gets into cracks, under the unit, or behind nearby drawers will harbor insects and keep an infestation going even after you clean the machine itself. Leaking pipes or faucets near the dishwasher create additional moisture sources that make the whole area more attractive to bugs.
Which Bugs You’re Most Likely to Find
Cockroaches are the most common dishwasher invader. They’re drawn to the combination of moisture, warmth, and food residue that collects around the appliance and its plumbing connections. They’ll hide in the rubber door seals, around the filter, and in gaps where the dishwasher meets the counter or floor. Even a single cockroach in your dishwasher usually signals a broader kitchen infestation, since they tend to nest behind appliances and inside walls before venturing out to feed.
Ants follow scent trails to food residue and can enter through tiny gaps in the door seal or along plumbing lines. Silverfish are attracted to the moisture more than the food. They thrive in damp environments and often hide in the crevices around the dishwasher rather than inside it. Carpet beetles, while less intuitive, feed on organic debris and can show up wherever food particles accumulate.
A Hidden Problem: Fungal Growth on Seals
Bugs aren’t the only unwelcome guests. A study of dishwashers found that 62% contained fungi growing on the rubber door seal. More than half of those harbored black yeasts that show remarkable tolerance to heat, high salt concentrations, aggressive detergents, and both acidic and alkaline water. These organisms can survive conditions that would kill most fungi.
These black yeasts are rarely found in nature but are frequently associated with human infections, including lung colonization in people with cystic fibrosis. They can occasionally cause serious infections even in otherwise healthy people. The rubber gasket around your dishwasher door is the primary place they colonize, which is one more reason regular cleaning of that seal matters.
How to Safely Clean Bugs Out
The most important rule: do not spray pesticides or pest control products inside your dishwasher. That includes borax and over-the-counter insect sprays. Every surface inside your dishwasher touches your plates, glasses, and utensils. Chemical residues left behind can end up on your food. Instead, take a non-toxic approach.
Start by removing the dishwasher filter and cleaning it thoroughly. This is where food debris collects, and it’s often the first thing attracting bugs. Most filters twist out easily from the bottom of the machine. Rinse it under hot water and use a soft brush to scrub away buildup.
Next, wipe down the rubber seals and the edges of the door. These spots trap moisture and grime that both insects and fungi feed on. Use a cloth dampened with vinegar or a paste of baking soda and water to scrub the gasket, paying attention to the folds where debris hides. Lemon juice also works well for cutting through grime and leaving the interior less appealing to pests.
Once everything is wiped down, run an empty cycle on the hottest setting your machine offers. Standard dishwashers heat water to a minimum of 150°F, and a sanitize cycle pushes that higher with a hot final rinse. While this won’t sterilize the interior (that would require temperatures around 250°F sustained for several minutes, beyond what home machines can do), it will flush out remaining debris and kill some microorganisms.
Preventing Bugs From Coming Back
Clean the dishwasher filter weekly. This single habit eliminates the primary food source that draws bugs inside. It takes about two minutes and makes a significant difference.
Don’t let dirty dishes sit in the machine for extended periods. If you’re waiting to run a full load, at least rinse plates before loading them so food residue doesn’t accumulate. After a cycle finishes, crack the door open to let moisture escape rather than leaving it sealed overnight. Persistent humidity inside a closed dishwasher is one of the biggest attractants for both insects and fungal growth.
Address the area around the dishwasher, not just the inside. Pull it out if possible and clean underneath and behind it. Sweep or vacuum food debris from the floor and surrounding cabinets. Fix any leaking pipes or faucets nearby, since even a slow drip creates the kind of moisture source that keeps pests returning. Seal any visible gaps where the dishwasher meets the wall or cabinetry with caulk to reduce entry points.
If you’re seeing cockroaches inside the dishwasher repeatedly, the infestation likely extends beyond the machine. Place sticky traps behind the dishwasher and under the sink to gauge the scope of the problem. Cockroaches nest in walls, behind appliances, and under cabinets, so treating only the dishwasher won’t solve a larger issue. A persistent cockroach problem in the kitchen typically requires professional pest control to address the source.