In the evening, small grey and copper moths zigzag around the kitchen. In the cereal box, grains stuck together with silk threads. On the ceiling, little white caterpillars looking for a corner. These are pantry moths, almost always the Indian meal moth. The good news: they don’t touch clothes or the house. The bad news: as long as the source stays in the pantry, they come back.
How to recognize them
- The moth: 8 to 10 mm, wings folded like a roof. The third nearest the body is pale grey, the rest coppery brown. It flies in the evening, in a zigzag, and rests on kitchen walls and ceilings.
- The larva: a small whitish caterpillar with a brown head, up to 1 cm. It does the eating and the spinning.
- Signs: silk threads and clumps in food, tiny droppings, cocoons in ceiling corners, cupboard hinges and shelf grooves.
Don’t confuse them with clothes moths, which are smaller, plain golden, avoid light and live in closets.
What they eat
Almost anything dry in a pantry: flour, cereal, rice, oats, nuts, dried fruit, chocolate, spices, cookies, cake mixes, dog and cat food, birdseed. Those last two are often the forgotten source, especially when stored in the basement or garage.
The moths nearly always arrive in a product that was already infested at purchase, then spread to nearby packages: cardboard and thin plastic don’t stop them.
The plan that works
1. Empty and inspect everything
Take everything out of the cupboards and pantry, including unopened packages. Look for silk, clumps, larvae and small holes in packaging. Throw out anything infested in a sealed bag, outside.
2. Treat anything doubtful
Food that looks fine but sat next to an infested product may hold invisible eggs. Put it in the freezer for a week. The Canadian Conservation Institute recommends −20 °C for one week to kill insects in an object; a well-set home freezer comes close.
3. Clean the cupboards
- Vacuum every corner, shelf groove, shelf-pin hole, hinge and the tops of cupboards: that is where the larvae pupate.
- Wash with soapy water, then dry thoroughly.
- There is no point spraying insecticide in a pantry: you would be putting a product where you keep food.
4. Store differently
- Airtight containers in glass, metal or thick plastic with tight-fitting lids.
- Pet food and birdseed in sealed bins, away from the kitchen.
- Buy quantities you will use within two months.
5. Monitor
Pheromone traps attract the males. They don’t solve an infestation but show whether it is still going. If they still catch moths three or four weeks after the clean-out, there is a source left.
Other pantry pests
Small brown beetles 2 to 4 mm long in flour or spices are other stored-product pests (sawtoothed grain beetle, drugstore beetle, flour beetles). The method is the same: find the source, discard, freeze, clean, store airtight.
When to call
- You did the big clean-out and the moths are back after a month.
- You find them in several rooms of the house.
- It is a restaurant, grocery store or food warehouse: that calls for a monitoring program such as our commercial preventive service.
For an assessment, contact us or call 514-638-8705. See also our guide to bugs in the house and our article on fruit flies.
Frequently asked questions
Can I eat food that had moths in it?
Pantry moths aren’t known to spread disease, but food full of silk, droppings and larvae is no longer edible. Throw it out.
Do bay leaves work?
There is no solid evidence that they repel moths. Airtight containers work every time.
Why do I see them on the ceiling?
The larvae leave the food to pupate and look for a dry, sheltered corner: where the wall meets the ceiling, the tops of cupboards, door frames.