A red knot is a tiny shorebird that makes an epic 9000-mile journey all the way from the arctic to the tip of southern Chile and back. Biologists and nature enthusiasts congregate at various points ...

Is it possible to count objects you can't see? If you've ever received a boxed gift, or a mysterious package from Amazon, you might have tried to lightly shake the box to try to guess its contents.

Counting feels utterly effortless to adults, who are unlikely to even remember when or how they picked up this useful, apparently automatic skill. Yet when you think about it, counting is a remarkable ...