Bugs in the kitchen: what they are, what they are after, and the fix for each

A kitchen is the one room in the house where food, water and warmth sit side by side all year. Nearly every bug you find there is following one of those three things, which makes the kitchen the easiest room to diagnose. Ask what it is eating, and you have found both the reason it came and the fix.

What they are

The usual kitchen visitors fall into four groups.

Small flies

• Fruit flies. Tiny, tan, with red eyes, drifting slowly around the fruit bowl, the wine glass or the recycling. Card #132.
• Drain flies. Grey and fuzzy, wings held flat like a miniature moth, sitting on the wall beside the sink. They are the same flies as in the bathroom guide.
• Fungus gnats. Thin, dark and mosquito-shaped, rising from the soil of a pot of herbs on the windowsill. They are weak fliers and tend to stay near the plant.

Bigger flies

• House flies. Medium-sized, grey, with dark stripes on the back, landing on everything. Card #124.
• Bluebottles. Large, loud and metallic blue, banging against the window. Card #127, with a close relative in the common green bottle fly.

Pantry pests

• Pantry moths. Small, plain moths fluttering out of the cupboard when you open it, often the Indian meal moth, with wings that look two-toned, pale near the head and coppery towards the tips.
• Flour beetles and weevils. Tiny reddish-brown beetles in the flour, or beetles with a little snout in rice and grain.
• Mealworm beetles. Larger, black and slow, more often in old stored grain, bran or animal feed than in everyday packets. See the mealworm beetle card.

Crawlers

• Ants. A line of small dark ants from a crack to the sugar, the honey jar or the pet bowl is usually the black garden ant or the pavement ant. Large black ants seen singly, with no trail, can be carpenter ants.
• Cockroaches. Small, tan, with two dark stripes behind the head is the German cockroach. Large, reddish-brown and fast is the American cockroach.
• Silverfish. Silvery and wriggling, under the sink or in the cupboard with the cereal boxes. Card #140.

What they are after

The pattern is simple enough to memorise: flies follow wet food, moths and beetles follow dry food, ants follow sweet food and water, cockroaches follow all of it.

Front desk note: pantry moths are usually found in the packet you opened most recently, but they started in the one you have not touched since spring. Check the back of the cupboard, and do not forget the birdseed and the dog biscuits.

The fix for each

Fruit flies. Find and remove the breeding spot, which is often small: one soft banana, a splash of juice under the fruit bowl, a sticky recycling box. Rinse bottles and tins before they go in the recycling. A small dish of cider vinegar with a drop of washing-up liquid catches the adults while you clean up. If you are not sure whether you have fruit flies or fungus gnats, the soil versus the fruit bowl is usually the answer.

Drain flies. Scrub the inside of the drain with a stiff brush, then flush with hot water. The film lower down is where the larvae live, and pouring liquid over the top tends to miss it.

Fungus gnats. Let the top of the soil dry out between waterings, and empty the saucer under the pot. Wet soil is what they need.

House flies and bluebottles. Keep a lid on the bin, empty it often, do not leave pet food out, and put a screen on the window you open most. A single fly is best shown the door with an open window and the light off inside.

Pantry moths and beetles. Go through the cupboard and look inside every packet for webbing, clumps, holes or live insects. Bin what is affected. Vacuum the shelves, paying attention to corners and shelf-peg holes, then wipe them. Keep dry goods in jars or tubs with tight lids, so that if one packet comes home with eggs in it, the problem stays in that jar. Some people freeze new bags of flour for a few days before storing them.

Ants. Wipe the trail with soapy water, which removes the scent the others follow, then put the sugar, honey and syrup in sealed containers and wipe up spills. Find where they come in and seal that gap. Most kitchen ants are scouts from a nest outside, and they leave once the food stops. If large black ants keep appearing near a window frame or under the sink, look for damp wood, because that is where carpenter ants nest; the black insects guide covers how to tell them apart.

Cockroaches. Clean behind and under appliances, fix leaks under the sink, keep food sealed and take the bin out at night. Seal gaps around pipes. One large roach wandering in from a drain is bad luck. Several small ones, or any seen during the day, often points to breeding indoors, and that is the point to get professional help rather than keep trying alone.

Silverfish. Dry the cupboard under the sink, fix the drip, and swap cardboard packets for sealed containers. The silverfish guide has the details.

Whatever you find, the bugs that are just passing through can be released: a glass and a piece of card is enough for a stray beetle or a moth at the window.

If two of these still look alike in your photo, the identifier will give you a name with a confidence level, and the Field Guide has a page for each species with its seasonal pattern and safety note. For the other rooms, see common house insects, room by room.