Ever wonder why eggs are shaped like eggs? Scientists say they’ve figured it out.

If a Hollywood exec dreamed up an egg, it would look like a chicken's: immensely popular, with an unblemished complexion. But the universe of wild bird eggs is far weirder and more diverse than the oval products on the supermarket shelf. Hummingbirds lay eggs shaped like Tic Tac mints — “perfect little ellipses,” per ornithologist and evolutionary biologist Mary C. Stoddard. Sandpiper eggs come to peaks, in the manner of teardrops. Owls plop out tight spheres not unlike ping-pong balls.