Engineers Construct “Bat Accelerator” to Crack Thriller of Stealth Navigation

The quicker you go on a motorcycle or in a automotive, the extra issues seem to visually stream previous. Your mind synthesizes this “optic flow” to estimate your pace relative to a cognitive map of your environment. Bats face a similar navigation activity as they fly via their environments, besides they depend on acoustic inputs as they echolocate in the dead of night. How they synthesize the myriad particular person echoes right into a coherent notion of pace relative to environment has been a thriller.

A study revealed in Proceedings of the Royal Society B reported proof that echolocating bats are utilizing acoustic circulate to navigate. “As bats fly and emit their calls, echoes return at slightly different rates depending on how close objects are and how fast the bat is flying. This creates a kind of sound flow,” defined examine writer and University of Bristol sensory biologist Marc Holderied in a statement. 

Holderied and his coauthors designed a bat accelerator machine: a conveyor-belt system with 8,000 revolving panels on both facet of an eight-meter part of woodland path. The path was identified to be a commuting hall for wild pipistrelle bats (each Pipistrellus pipistrellus and P. pygmaeus) in Bristol. The panels, coated in plastic ivy leaves for a hedge-like acoustic texture, might both rotate in the identical or in the other way of bat flight. 

Read extra: “Why Bats Are Flying Machines”

The researchers examined a trio of circumstances: the panels rotating in the identical route of bat flight, rotating in the other way, or not rotating in any respect. Over three nights, 104 bats flew the entire size of the panel array. When the panels had been rotating within the route of flight, they flew quicker on common. In distinction, when the panels had been rotating in the other way, bats flew considerably slower by as much as 28 p.c. 

“We know bats fly swiftly, but we’ve shown that we can make them fly even faster with our corridor of ‘revolving hedges’—our bat accelerator,” concluded examine writer and aerospace engineer Shane Windsor. The phenomenon is a spin on the precept of Doppler shift, whereby the bats are utilizing motion-induced adjustments in echo frequency to manage their flight. Because the impact was the strongest as bats approached the pretend hedge rows, they’re possible deciphering echoes from a number of meters forward of their flight path.

The experimental outcomes demonstrated that bats depend on acoustic circulate for pace management, which can serve them in navigation. Compared to sonar-based robots that carry out poorly as quickly as you add litter to their paths, bats can apparently use Doppler info to estimate their self-motion. 

Robots, eat your hearts out.

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Lead picture: Rudmer Zwerver / Shutterstock

• Devin Reese

  Posted on January 26, 2026

  Devin Reese is the chief editor of Natural History and a science author primarily based in Alexandria, Virginia.