Krill are tiny shrimp-like creatures that swim in enormous groups called swarms in the ocean, especially in cold waters near Antarctica. Each individual krill is usually less than two inches long, but when billions gather together, they create swarms so massive they can be seen from space, looking like giant pink clouds in the water.

Despite their small size, krill are some of the most important animals in the ocean. They eat microscopic plants called phytoplankton and then become food for almost everything else: whales, seals, penguins, fish, and squid all depend on krill for survival. A single blue whale, the largest animal on Earth, can eat about four tons of krill in a single day. Without krill, most Antarctic animals would struggle to survive.

Scientists estimate there might be hundreds of trillions of individual krill in the ocean, making them one of the most abundant animals on the planet by total weight.