Sea turtles have long mystified researchers by returning to beaches where they were hatched, magnetic signals may be the key, new research finds.

Researchers set out to catch baby turtles in the Gulf of Mexico to tag them and learn more about where they go when they scurry to the sea after hatching.

These aquatic reptiles swim thousands of miles across the open ocean to return to the same foraging grounds and nesting sites. They don’t always take the shortest, most direct route, but they do eventually get to where they’re going.