Flies & Gnats
Houseflies, fruit flies, and fungus gnats each trace back to a different indoor source, and finding it matters more than any trap. These guides cover identification, breeding sites, and lasting fixes.
Indoor nuisances, and the fix is nearly always the source, not the swarm. Find what they're breeding in.
Size
2 to 8 mm
small and quick
Diet
Rot, waste, damp soil
drains and fruit
Habitat
Kitchens and compost
overwatered houseplants
Breeding
A week per generation
fruit flies fastest
Wings
One pair, not two
what makes a true fly
Life cycle
The whole cycle can run in a week, which is why one forgotten banana becomes a cloud.
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Egg Laid on the food source, fruit, waste, or damp soil, often in clusters of dozens.
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Larva A maggot. It eats constantly in the rot it hatched in, growing over just a few days.
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Pupa It hardens into a dark case while it transforms, tucked in or near the food.
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Adult The fly you notice. By the time it is flying, the next generation is already laid.
Every indoor fly problem I've helped with came down to one source people had walked past for days: a drain, a forgotten potato at the back of the cupboard, a houseplant kept too wet. Kill the source and the swarm has nowhere to come from. Chasing the adults is wasted effort.
Sam Fielding · field note · about Sam
Typical season
Indoors all year; worse in the warm months when they breed fastest.
Often confused with
A fruit fly goes from egg to adult in about eight days, which is why one forgotten banana becomes a cloud so fast.
Fruit Flies
The kitchen cloud. Tiny, red-eyed, and drawn to anything fermenting. Harmless but relentless until you find and clear the source.
Start here
A housefly tastes with its feet and can't chew, so it vomits enzymes onto food to dissolve it, then slurps it back up.
Houseflies
The classic buzzer. Larger, grey, and drawn to waste and food alike. More a hygiene concern than a bite risk, so bin management is the fix.