Fruit Fly

Drosophila melanogaster

Size2–4 mm

Active Season:Indoors: Active year-round with peaks when fresh produce is abundant. Outdoors: Peak populations August-October when fruit ripens and temperatures favor rapid breeding. Outdoor adults die with first hard frost but indoor populations persist indefinitely.

A tiny, ubiquitous household fly that breeds rapidly in fermenting fruit, vegetables, and sugary liquids. Also known as vinegar flies due to their attraction to fermentation. Despite their small size, they can quickly explode into large populations indoors.

Anatomy

Anatomical Details

Identification

ColourTan to light brown body with distinctive bright red eyes (most notable feature). Wings are clear with visible veins.

Size2–4 mm

Distinguishing Features

Bright red compound eyes—the most diagnostic feature
Very small size (2-4mm)—among the tiniest household flies
Tan/light brown smooth body without metallic coloring
Feathery arista (hair-like extension) on antennae
Slow, hovering flight pattern near food sources
Black striped bands on abdomen

Similar Species

Drain flies are fuzzy/moth-like with rounded wings and are found specifically near drains. Fruit flies are smooth with red eyes.
Fungus gnats are dark/black with long legs and antennae, found near houseplant soil. Fruit flies are tan/brown with red eyes near fruit.

Biology

Lifecycle

Complete lifecycle from egg to adult takes only 8-10 days at room temperature—among the fastest breeding insects. Females lay up to 500 eggs at a time near fermenting organic matter. Eggs hatch in 24-30 hours into tiny larvae that feed for 5-6 days before pupating. This rapid reproduction allows populations to explode in days.

Diet

Adults feed on fermenting fruits, vegetables, and sugary liquids including wine, beer, juice, soda, and vinegar. They are particularly attracted to yeast and bacteria that break down organic matter. Unlike filth flies, they prefer fresh to slightly overripe produce rather than decaying material.

Nesting

Breed wherever fermenting organic matter accumulates: overripe fruit, sink drains, garbage disposals, empty bottles and cans, mops and cleaning rags, recycling bins, and compost containers. Can complete entire lifecycle in drain biofilm or garbage disposal sludge. Indoor populations persist year-round with climate control.

Signs of Infestation

Flies hovering near fruit bowls

Small flies with red eyes hovering slowly around fresh or ripening fruit, vegetables, or fruit bowls on countertops.

Flies near sink drains

Numerous tiny flies emerging from kitchen or bathroom sink drains, particularly in morning or when drain is disturbed.

Swarm near wine or beer

Flies congregating around open wine bottles, beer cans, juice containers, or other fermenting liquids.

Flies in recycling bins

Large numbers near recycling bins containing empty beverage containers with residual liquid.

Rapid population explosion

Going from a few flies to dozens or hundreds within just a few days—indicating active breeding nearby.

Where They Nest

Near fruit bowls and produce storage areas
Kitchen sink drains and garbage disposals
Recycling bins with beverage containers
Trash cans with food waste
Around houseplant soil (overwatering creates breeding sites)
Mop buckets and cleaning rags
Behind/under refrigerators where produce may have rolled

Common Nesting Sites

Nesting Site Details

Distribution in Canada

Found year-round throughout all of Canada wherever humans maintain heated indoor spaces. Outdoor populations peak in late summer and fall but cannot survive Canadian winters. Indoor populations are sustained year-round in homes, restaurants, and food processing facilities.

Regional Prevalence

High

Moderate

Low

Rare/Absent

Active Season

Indoors: Active year-round with peaks when fresh produce is abundant. Outdoors: Peak populations August-October when fruit ripens and temperatures favor rapid breeding. Outdoor adults die with first hard frost but indoor populations persist indefinitely.

Prevention

Store ripe fruit in refrigerator rather than on countertops
Dispose of overripe or damaged produce immediately
Clean sink drains weekly with enzyme cleaner or boiling water
Rinse recycling containers before storage
Take out kitchen garbage daily, especially during warm weather
Clean garbage disposal weekly—remove and scrub splash guard
Keep fruit bowls covered with mesh or netting
Wipe down counters to remove fruit juice and sugary spills
Don't overwater houseplants—allow soil to dry between waterings
Clean up spilled wine, beer, or juice immediately

Professional Treatment

Professional treatment focuses on identifying and eliminating breeding sites rather than just killing adult flies. Technicians locate all sources, recommend sanitation improvements, and may apply targeted treatments to drains and problem areas. Follow-up visits ensure breeding cycle is broken. Most infestations resolve with proper sanitation alone.

Get General Pest Control Service

Scientific Classification