Getting wet costs a mouse more than 10% of its body weight
What feels like a light film to us is a heavy, glue-like trap at the size of a mouse or an ant.
Kurzgesagt – In a Nutshell · What Happens If We Throw an Elephant From a Skyscraper? Life & Size 1Getting wet costs you about 1% of your body weight, but it costs a mouse more than 10%.
When you step out of the shower, about 800 grams of water clings to you. For a mouse, it is about 3 grams. Because the mouse is so small, that little film is a heavy load, like you leaving the shower with eight full water bottles stuck to your skin.
Shrink down further and water stops being heavy and starts being deadly. If you were as small as an ant, touching water would feel like reaching into glue. The surface quickly engulfs you, and its outer skin is too strong to break, so you drown.
That is why insects developed coatings and hairs that shed water.
Questions people ask
Why does relatively more water stick to smaller animals?
It is geometry. Weight grows with volume, but the water that clings to you grows with skin area. Smaller animals have much more skin for every ounce of body, so the same film of water weighs far more relative to them.
How do insects stay water repellent?
Many have a thin waxy coating that water cannot grip well, plus dense mats of tiny hairs that keep droplets from touching the skin. Together they let water bead up and roll off instead of spreading and sticking.