The recurring problem is the same everywhere: sleep appears to be necessary, and being asleep is dangerous. Almost every solution below is a compromise between those two facts. Here are…
Animal navigation combines several systems at once, which is why removing one rarely stops an animal entirely. Here are seventeen of the tools involved.
1. Reading the Earth's Magnetic Field…
There are a small number of biological rules that hold across every vertebrate: a spine, a heart, and haemoglobin to move oxygen around the body.
The last one has exactly…
Goosebumps are among the strangest things the human body does routinely. A sensation arrives — cold air, a piece of music, someone's fingertips on the back of your neck —…
Hiccups are so ordinary that almost nobody asks what they are for. Everyone gets them, they arrive unbidden, they are mildly annoying, and they go away.
But consider what is…
Try it. Run your fingers along your own ribs, or the sole of your own foot, using exactly the motion that would reduce you to helpless laughter if somebody else…