Why are fruit flies so difficult to get rid of?

Updated July 30th, 2024

Meet Drosophila Melanogaster, your common fruit fly (not to be mistaken with another tiny nuisance, the gnat).

Though small in size, the fruit fly is a mighty force to be reckoned with—once inside your home. This minuscule sesame-seed-sized little beast is only one to four millimeters in length, (which is the same as the width of half-of-a-nickel to the width of a penny and two dimes laid on their side.) While it may have a tiny brain, its highly-evolved visual system, compact body, powerful wings, incredible flying capability, small antennae and keen smelling ability make up for it.

Let’s talk about the details for a moment, shall we?

Why are fruit flies so hard to get rid of?

Here are seven reasons why fruit flies prove to be such persistent pests in our homes:

1. Visual evasion: Mastering escape

A fruit fly’s visual system allows them to process optical information at lightning speed, meaning that they are able to perceive and respond to changes in their environment with incredible accuracy. They can detect and respond to movements that are too fast for the human eye to see.

In fact, a fruit fly’s 270-degree vision surpasses even the most advanced technology. It can see you coming from almost any angle: front, back or side-to-side and will calculate the angle of your attack, planning their escape accordingly in as little as 100 milliseconds.

Pocket fact: Scientists figured this out by observing how a resting fruit fly will reposition its legs when it senses an attack. If your hand's coming from the front, for example, fruit flies lean back and raise their front legs, allowing for a fast backwards takeoff.

2. Body maneuverability: Agile and small

A fruit fly has a compact and lightweight body, enabling it to make very quick, unexpected turns and sudden, unanticipated movements to evade predators. Its small size also allows it to exploit small spaces and crevices in search of food, breeding sites and shelter.

3. Wing speed: Swift movements

A fruit fly’s powerful wings beat at a rapid pace of over 200 times per second, enabling it to hover, fly backwards and make tight turns with unbelievable ease.

4. Flying skills: High-speed escapes

This tiny creature can fly at a speed of up to 3.4 miles per hour. While this may not sound very fast, it is quite impressive considering its size. To put it into perspective, a fruit fly's top speed is more than 90 times its body length per second, which is equivalent to a human running at over 1,200 miles per hour.

5. Antennae sensitivity: Precision navigation

A fruit fly’s antennae is seemingly insignificant, but this is far from the truth. These small appendages play a vital role in the fruit fly's ability to interact with its environment. They are crucial for multiple aspects of survival:

• Temperature and pressure sensing: Detects changes in temperature, humidity and air pressure, helping the fly maintain position in the air.
• Communication aids: Captures vibrations and sound waves, allowing fruit flies to communicate and sense threats.
• Spatial awareness and movement: Registers changes in air currents—through the fine hairs on the antennae—allowing fruit flies to sense their surroundings in three dimensions. This ability is crucial for flying and dodging obstacles in complex environments.

6. Olfactory detection: Tracing scents precisely

Its highly sensitive olfactory receptors are what propels a fruit fly (and all of its friends) to the fermenting fruit on your countertop. This persistent minute nuisance will follow an odor gradient until it reaches its source. Once it latches onto a scent, there’s no turning back.

Pocket fact: A fruit fly can detect certain odors at concentrations as low as a few parts per trillion.

7. Rapid reproduction: Quick life cycle

A fruit fly’s life cycle allows it to replicate (and cause an infestation) at a fantastic rate. A simple female, being the prolific egg-layer that she is, can lay as many as 100 eggs per day in batches of 5 to 15 (and 500 throughout her entire life). These eggs hatch into tiny white maggots (or larvae) within 24-30 hours that become fully fledged sexually mature adults within 8 to 10 days that are ready to take on the world (or your kitchen). A typical lifespan is 50 days.

Now that you’re thoroughly awed by this minute flying wizard, let's discuss how to truly get rid of them.

How do I get rid of fruit flies?

First and foremost,  cleanliness is paramount.  These persistent pests, drawn to all things decaying and sugary, won't hesitate to return if they find more to feast on. Remember, fruit flies aren’t fussy eaters.

Common attractants for these upset-stomach-producers:

Decaying fruit: Fruit flies are attracted to decaying fruit and the tasty fungi that grow on it.

Mushrooms, mold and mildew: They thrive on the microbes feeding on decomposing organic matter found in mushrooms, mold and mildew.

Rotting vegetables: Tomatoes, eggplants and potatoes—among other vegetables—can become breeding grounds when they start to decompose.

Trash can sludge: The sludge at the bottom of your trash can and slime in your garbage disposal are ideal habitats.

Sugary substances: Fruit juice, soda and alcohol also attract these pests due to their high sugar content.

After ensuring your home is spotless, all experts would encourage the use of traps. The best fruit fly lure and killer (and my personal favorite) is our very own Sweet Surrender Fruit Fly Trap Liquid Refill, a scientifically formulated, highly effective formula that was developed and tested in my very own kitchen. (I’m going to spare you the details on the plethora of fermenting fruit and horde of minute fruit flies present.) This refill is completely safe and wholly non-toxic for you, your family and your pets, but is truly noxious for fruit flies. One dose will have them sleeping with the fishes.

Simply pour 2 ounces into a container—I personally recommend our Sweet Surrender Fruit Fly Trap, which includes both the reusable trap and two doses of attractant. Place it near the location of the infestation, remembering that fruit flies are also attracted to light (and to a lesser degree, heat) and let the doctor do the work for you.

Note: Beware of a fruit fly’s presence on many common garden and ornamental aphid-attracting plants, as aphids secrete a sweet, sticky, sugary substance called honeydew, which is highly attractive to fruit flies. Some of these plants could be in your home (such as African violets and poinsettias) and the ultimate cause of your fruit fly infestation.