The impressive cognitive abilities of dolphins have long been known. The cetaceans can problem-solve and demonstrate advanced communications. But a recent study suggests that dolphins have another previously unknown capability: they’re drawn towards magnets.

Magnetoreception, or the ability to use Earth’s magnetic fields as a compass, has been studied in birds, bees, and other fish. Now it appears that dolphins rely on this system as well.

French researchers presented dolphins with magnetized and unmagnetized objects. The dolphins swam faster towards the magnetically charged objects, indicating that they too rely on magnetoreception to determine position and location.

“Dolphins approached the device with shorter latency when it contained a strongly magnetized neodymium block compared to a control demagnetized block that was identical in form and density and therefore undistinguishable with echolocation,” the French study concluded. We conclude that dolphins are able to discriminate the two stimuli on the basis of their magnetic properties, a prerequisite for magnetoreception-based navigation.”

The study used six bottlenose dolphins who were allowed to swim freely in tanks. Barrels containing magnetized and unmagnetized contents were placed in the tanks. The dolphins instantly swam towards the magnetically charged barrels, indicating that they utilized magnetoreception in determining location and positioning of their destination.

The impacts of magnetoreception, while not fully understood, can be beneficial or devastating depending on their reliability. Sunspots, caused by solar storms, that interrupted magnetic fields were recently blamed for a decrease in bee colonies. This suggests that changes in the Earth’s magnetism can also impact animal population density and location.