Bees Have a Water Escape Plan. Pesticides Dampen Their Swimming Skills.

A bee that ends up in water isn't necessarily finished. New research from Michigan State University, published in Communications Biology, confirms that honeybees can propel themselves across the water's surface with purposeful, directional movement, swimming toward darker areas and likely using visual contrast to locate the shoreline.

The experimental setup was minimal: one bee at a time, a shallow water-filled bowl, a darkened section along the rim. The majority headed for the dark section reliably, demonstrating skototaxis: a hardwired orientation response that gives bees a usable bearing on an otherwise featureless water surface. The behavior appears to be an actual escape strategy, not an accident. That pull toward darkness likely leads them to a surface they can grip, pull themselves out of the water, and eventually take off from.

Mason bees (Osmia excavata) showed the same skototaxis, with an even stronger dark preference than honeybees, and female mason bees were more efficient swimmers than males. The researchers suggest the behavior evolved before sociality and serves genuine adaptive functions.

The study's second finding is the one with consequences. Researchers tested whether exposure to thiamethoxam, a commonly used neonicotinoid insecticide, affected the bees' ability to navigate on water. Exposed bees no longer showed any preference for dark areas. Instead, they showed no directional bias, wandering erratically and covering far more distance before reaching the bowl's edge. Tracking data showed the exposed bees changed direction far more frequently, pointing to degraded motor function rather than a straightforward failure of visual processing.

As long as they don't get poisoned, bees swim to safety.

Read the full story at Phys.org, June 2, 2026

Hot Take: The part that deserves more attention is that skototaxis likely predates eusociality in bees, which means a solitary insect, navigating entirely alone, developed a directional escape behavior sophisticated enough to still be running in honeybees tens of millions of years later. Pesticides disrupting motor control in an insect this ecologically load-bearing should not be a footnote.