Ever find something that is equal parts cool and horrific? A commenter on this site recently mentioned there was an easy method to finding spiders at night. This method apparently does indeed work, and now I'd like someone to try it. Because I won't.

Nocturnal creatures have good night vision due to many different adaptations. Some can see wavelengths that human eyes can't pick up. Some have exquisitely sensitive retina. Some have a structure in the eye known as the tapetum lucidum. This is a layer of reflective tissue inside the eye, just behind the retina, which reflects back light which would otherwise be lost. Cats have it. Deer have it. And apparently spiders have it.


Which is why you can go out at night, with a flashlight and nerves of tempered steel, and when you shine the flashlight beam at your lawn, you'll see lots of little points of light reflected back at you. They look like dew drops, but they're not. They're spider eyes shining the dark. So in these waning days of summer, go out with a flashlight. Shine it at your lawn. You can see them from tens of feet away. When you see some reflective dots, go forward, carefully keeping the flashlight steadily on that spot. You'll find a spider.

Then run.

[Via E Is Real I Isn't, Reflections on the Tapetum Lucidum and Eyeshine in Lycosoid Spiders]