Scientists have been finding swarms of jellyfish, called blooms, all over the world.
The very bottom of the food chain is changing and can have far-reaching consequences for the rest of us. Learn more on this Moment of Science.
The answer is diet. Those species with the most elaborate plumage also have the most diverse and reliable diet: a variety of insects, and fruits rich in complex nutrients. With this reliable food supply, females can raise the hatchlings without help from the males.
Do lemmings really follow each other off a cliff to their death? No, but there are mysteries surrounding the rodents. Over the years, there have been many tales of these Arctic rodents voluntarily jumping off cliffs and plummeting into the sea.