How do they get there? While pests like beetles or moths may already be on items we bring home from the store, DeVries says most show up after food enters your cabinets: “crimes of opportunity.”
Insects that are attracted to your food may already be inside or may enter through open doors, cracks, or torn screens.
Partially open packages, like flour bags or cookie sleeves, are an invitation to bugs, as are thin cardboard boxes with narrow gaps, like pasta or cracker boxes. Anything that spills or drips, looking at you, honey and sugar, can also attract them.
What do they eat? Some pests can penetrate the seed coat of plants, which is why whole grains are particularly attractive to certain species, says DeVries. Others require the grain to open, as in many refined flours, pastas, cookies, cereals, crackers, etc. Dog and cat food and bird seed are also common sites of infestation.
“Inside buildings, house ants feed on sugar, syrup, honey, fruit juice, fats and meat,” says the University of California Division of Agriculture and Natural Resources.
How should you get rid of them? Usually when you come across pantry moths or beetles, what you find are adults, DeVries says. Once you see a lot of them, 10 or 20, you probably have an infestation.
Just as eliminating the breeding site of fruit flies is the only sure way to eliminate these common pests, getting rid of the source is key to saying goodbye to beetles and moths. Systematically sort all the food in your pantry and open the packages. Sift grains or flours to detect intruders. Anything that appears to be heavily infested should be discarded. Often the damage is limited to one or two items, according to DeVries. If you want to try salvaging items, or want to make sure that what appears to be pest-free is in fact pest-free, you can freeze them at 27 degrees or, ideally, cooler for three to seven days; the longer the better, says the University of Illinois-Champaign Illinois Extension. or you can heat the food to 140 degrees in an oven for an hour, though keep in mind that most home ovens can’t be set that low.
Getting rid of infested food can go a long way toward eliminating an infestation, but vacuuming and/or wiping down shelves with warm, soapy water is never a bad idea.
Much of the same advice applies to ants. Once you find what attracts the ants, says the University of California Division of Agriculture and Natural Resources, remove it. Vacuum up ant trails and clean with warm, soapy water. This eliminates the pheromones that the insects would follow to return to the food source, says DeVries. Then try to find and seal the points where they enter. If they persist, you can use ant bait, either in stations or in other forms such as gel, but try to save it for serious infestations. If you can, use bait outside near entry points so you don’t inadvertently draw more ants inside.
What don’t you need? Insecticides, says DeVries. Insecticides, especially sprays, near food and food preparation surfaces pose a greater danger to you than pantry pests, which are a nuisance but not a general health concern. For any beetles and moths you find, use a fly swatter or vacuum to remove them, or flush them out the door.
How can you prevent them? DeVries suggests a three-pronged approach to prevention: food rotation, keeping intruders out, and hard-sided containers.
First, use the food in your pantry in a timely manner. Beetles and moths take a while to settle, so if you’re using your flours, pastas, and snacks over the course of a few weeks or even months, you’re probably fine. It’s the old items that get stuffed in the back and remain untouched for a long time that are particularly problematic. Periodically sort through what you have to see what needs to be used or thrown away (or composted).
Avoid leaving doors or windows open without screens. Repair cracked screens and seal gaps around your baseboards, doors, and windows.
Keeping food in hard-sided, airtight containers is a “very simple, very easy” step you can take, says DeVries. That deters pests, of course, with the added benefit of keeping food fresh for longer. Containers or not, if you notice a spill, clean it up right away.