nests

What creates mysterious circles on the seafloor? No, it’s not aliens of the deep—it’s actually pufferfish hoping to snag a mate, a new study says. Divers first noticed the 6.5-foot-wide (2-meter-wide) circular structures near Japan‘s Amami-Oshima Island about 20 years ago. But no one knew how these so-called mystery circles were constructed—or what was creating...

What creates mysterious circles on the seafloor? No, it’s not aliens of the deep—it’s actually pufferfish hoping to snag a mate, a new study says. Divers first noticed the 6.5-foot-wide (2-meter-wide) circular structures near Japan‘s Amami-Oshima Island about 20 years ago. But no one knew how these so-called mystery circles were constructed—or what was creating...