Horned ghost crab, Grand Anse, Praslin Island, Seychelles

Fight for your lefts

It's International Lefthanders Day, so why are we showing this horned ghost crab whose right claw is noticeably larger than its left? Well, we're calling this crab a lefty because while its beefy right pincher is useful for grappling with other crabs, it uses its left claw for precision work like bringing food to its mouth, as a human southpaw does. (Though to be fair, it's never been observed which claw these crabs use for writing or playing golf.)

Among humans, lefties are outnumbered 9 to 1—so simple actions, from typing on keyboards to swiping on dating apps to zipping up a jacket to reaching for the toilet paper, are by design just a little harder for lefties. International Lefthanders Day is observed each August 13 to highlight this imbalance and work toward lefty-inclusive solutions. Call it a lefty rights movement.

If you're a righty, try going through today as if your left hand were dominant—you'll find it's not just lack of practice getting in your way but human design too. And once you've thrown both hands up in frustration, give 10 percent of your fellow humans a big hand for their everyday resourcefulness.