Clouds are generally agreed by scientists to be composed of water drops or ice crystals floating in the sky. But what if I told you that there are also clouds made of birds like starlings? Take a look.

What you see above, which was recorded in Northern Yorkshire, England, is called a murmuration of starlings. A phenomenon in which large groups of starlings fly together in intricate, cloud-like patterns, swooping and turning with startling precision. Murmuration is an awesome sight, almost otherworldly in its strangeness and beauty.

Starling murmurations can last for up to an hour and occur above roosting sites just before dusk during autumn and winter. Scientists are unsure why they occur, but believe it has to do with safety in numbers. One thing scientists have determined is that, regardless of how big the murmuration is, each starling pays attention to exactly seven neighbors as they perform this intricate, mysterious dance together.

Senior writer Chris DeWeese edits Morning Brief, The Weather Channel’s newsletter.