A tiny find in a worm-sized brain could give scientists a far greater understanding of how animals use the Earth's magnetic field, phys.org reports. In a lab at the University of Austin in Texas, certain hungry worms were found to move down in gelatin-filled tubes, perhaps in their natural search for food. But worms of the same species, C. elegans, from elsewhere in the world—including Hawaii, England, and Australia—didn't, because they were heading in what would have been down in their native region. And when researchers changed the magnetic field in the lab with a magnetic coil system, the worms changed direction. Then it happened: Scientists identified for the first time a microscopic sensor that helps an animal navigate via the Earth's magnetic field, they report in the journal eLife.
"It's been a competitive race to find the first magnetosensory neuron," says Jon Pierce-Shimomura, a member of the team. "And we think we've won with worms, which is a big surprise because no one suspected that worms could sense the Earth's magnetic field." They discovered the sensor on the end of the so-called AFD neuron, which resembles a microscopic TV antenna; researchers already knew it could help sense carbon dioxide levels and temperature, NBC News reports. And while other animals (like pigeons) are known to process data related to magnetic fields, no one had found a magnetosensory neuron before. "Chances are that the same molecules will be used by cuter animals like butterflies and birds," says Pierce-Shimomura. He even suggests that farmers could manipulate magnetic fields to rid crops of pests, per UT News. (Dogs use Earth's magnetic field ... to poop.)