Ars Technica42%
How fruit flies chase invisible ribbons of smell to get to their source 12%
By Jacek Krywko14%
8/1/2026, 3:00:19 AM
BS Summary: This article contains 10 faulty reasoning types, including Pessimism Bias, Negativity Bias, and Recency Bias, with Appeal to Authority as the most egregious example at 20.1% saturation with 54 hits. Analysis detected 244 faulty-reasoning hits from 269 analyzed words, generating a BS Score of 23.8% and a BS Rank of 12% (22,622 of 25,563 articles). This article is better (less manipulative) than 88.50% of the article peer group.
A fruit fly hunting a piece of rotting fruit or a mate navigates by smell, following plumes of odor.
Out in the wild, turbulent air swirls these plumes into a chaotic, broken landscape—dense chemical filaments laced through long stretches of clean air.
A fly trying to find the source gets the smell in stutters, from constantly shifting directions, with no guarantee that a next whiff is coming at all.
Scientist had little idea of how fruit flies manage this chaotic signal with a brain the size of a pinhead.
For a long time, biologists stood by the “surge and cast” model, which posited that insects solved this with hardwired reflexes.
The idea was that, when a fly registers the plume with olfactory neurons in its antennae, it simply flies upwind until it’s gone and then flies side to side attempting to catch it again.
But now a team led by Vanessa Ruta, a neuroscientist at the Rockefeller University, has shown that fruit flies do something far more advanced.
A treadmill for flies
The trouble with the traditional surge and cast model is that it struggles to explain how an insect tracks a meandering plume across long distances.
Chemical cues floating in the air in the natural environment are often sparse and unreliable.
But those same features make the mechanism behind olfactory navigation notoriously difficult to test.
"Odors are invisible," Ruta says, "and often they're carried along by turbulent airflow."
We’ve got no way of knowing what the animal is smelling from one moment to the next.
Analysis
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