Krill are shrimplike crustaceans that swarm in masses in the ocean, making an inviting supper for birds, whales, and other sea creatures. According to National Geographic, scientists estimate that the total weight of just the Antarctic krill alone is more than the total weight of all humans on Earth.

Krill are valuable not just as a food source for other marine life, but quite possibly for their role in the health of the ocean itself. Scientists have found that the nightly migration of krill swarms actually facilitates mixing in the upper layers of the oceans, circulating nutrients and exchanging heat and gases, including carbon dioxide, suggesting a possible role in climate change.