Pest Library
House Fly
House flies are gray flies with four dark stripes on the thorax that develop in decaying organic material — trash, spills, dumpster residue, pet waste and organic sludge. Sustained indoor numbers almost always mean a breeding source is close by, and finding it matters more than trapping adults.
Profile
- Scientific name
- Musca domestica
- Identification
- Dull gray body, four lengthwise thoracic stripes, sponging mouthparts, no biting.
- Typical size
- About 1/4 inch.
- Behavior
- Strong flier drawn to odors, warmth and light. Feeds by regurgitating and sponging, which spreads contamination.
- Habitat
- Trash areas, dumpsters, drains, pet waste, compost and organic buildup under equipment.
- Diet
- Decaying organic material, sugars, food residue.
- Lifecycle
- Egg to larva to pupa to adult in as little as a week under warm conditions.
- Why it matters
- House flies move between waste and food-contact surfaces and carry contamination, a particular concern in food service and healthcare.
- DIY considerations
- Sprays and traps knock down adults but never resolve an unfound breeding source.
- Professional considerations
- Service is a source investigation first: locate breeding material, document sanitation corrections, then use targeted treatment and monitoring devices.
Signs of activity
- Persistent flies in kitchens and dining areas
- Dark specks on light surfaces, ceilings and window frames
- Larvae in dumpster residue, drains or organic buildup
- Numbers spiking during warm weather or after a spill
Prevention
- Keep dumpster lids closed and clean pads and cans regularly
- Clean organic buildup under equipment and in floor drains
- Repair screens and use door sweeps and air curtains where appropriate
- Remove pet waste and standing organic debris promptly
Sources
Related information
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