Ants get into a dishwasher for food residue and water, usually through gaps around the plumbing under the sink or along the bottom edge of the door. Cleaning the filter and the door seal and closing up the entry point solves most cases. Spraying insecticide inside the tub doesn't, and it isn't safe on surfaces that touch your dishes.
Quick diagnosis
| Symptom | Likely cause | First thing to try |
|---|---|---|
| Ants along the bottom of the door | Food residue on the lower door edge and gasket | Wipe the door bottom and gasket with warm, soapy water |
| Ants inside the tub in the morning | Food trapped in the filter or sump | Remove and wash the filter, then run a hot cycle |
| Trail coming from the sink cabinet | Gaps around pipe holes in the cabinet | Seal the openings around the supply and drain lines |
| Ants near the control panel or wiring | Ants nesting in a warm electrical area | Turn off the breaker and call for service |
| Ants return a day after cleaning | Dirty dishes sitting for days | Run loads sooner or rinse heavy food off first |
A closer look
The filter and sump
Most newer dishwashers have a filter you twist out from the tub floor. If it isn't cleaned, it holds food scraps in warm, wet conditions, which is exactly what ants are looking for. Rinse it under the tap, scrub the mesh with a soft brush, and lock it back in place.
The door and gasket
The bottom edge of the door and the lower gasket catch drips that the spray arms never reach. Wipe them every week or two, and look under the bottom rack track for buildup.
Entry from the cabinet
The holes where the drain hose, water line and power cord pass between the sink cabinet and the dishwasher space are a common ant highway. Seal around pipes with a sealant made for the purpose, and set ant bait in the cabinet, away from the dishwasher's inside, instead of spraying.
Ants in the electronics
Some ants, fire ants especially, are known to move into electrical equipment, where they can short switches and contacts. If you see ants around the control panel, door latch wiring or under the toe kick near the wiring, turn off the power and have it looked at.
Why Houston homes see this more
The warm, humid climate keeps ants active most of the year here, and fire ants are common across Southeast Texas. Heavy rain tends to push colonies toward dry ground, and a house kitchen is about as dry as it gets.
Prevention checklist
- •Clean the filter every week or two if you cook a lot
- •Wipe the door bottom and gasket regularly
- •Don't leave a half-loaded dishwasher sitting for days
- •Seal gaps around plumbing in the sink cabinet
- •Use bait outside the appliance and call a pest control pro for an active colony
Time to call a pro
- •Ants around wiring, the control panel or the door latch area
- •The dishwasher stops responding or acts erratically after an ant problem
- •You find a leak under the unit that keeps the area wet
Travis's rule of thumb: Take away the food and the water and the ants lose interest. Chemicals don't belong inside the tub.
A dirty filter feeds ants and dirty dishes alike, so here's what grit on your dishes says about the filter. If ants have reached the controls, see our dishwasher repair page or call (832) 552-1615.