Discovering what looks like scattered grains of white rice crawling across your trash can is an unsettling shock. The illusion breaks the moment you notice them wriggling, shifting, and migrating across the plastic lid.

If you are staring at a scene like this and wondering how hundreds of small white creatures suddenly appeared overnight, you are dealing with a very common household intruder: fly larvae, universally known as maggots.

Understanding why they appeared, where they came from, and how to eliminate them safely can help you clear up the problem quickly without panic.

Those moving white specks are fly maggots—specifically the larval stage of common houseflies or blowflies. They resemble grains of white or pale yellowish rice, typically measuring between a quarter-inch to a half-inch long.

Adult flies are naturally attracted to the strong, organic odors emitting from decomposing household waste, especially animal proteins like meat, fish scraps, poultry, and dairy. A single female fly can lay hundreds of tiny eggs on exposed food waste inside a trash bag. Within 8 to 24 hours under warm conditions, those eggs hatch into ravenous larvae that immediately begin feeding on the surrounding organic matter.