I hadn't thought of springtails. I think they're too small for my Brownie, anyhow. But there they were; cute, fat, globular springtails, scurrying grey Orchesellas, hints of those blind, white ones, just disappearing beneath flakes of rust. And there was a tiny, golden spider, small enough to consider a springtail a good meal.
|Spider on the right, globular springtail hiding in the crack to the left.|
|Her fangs are as big as the springtails themselves.|
|Iffy photo. Included because of the claws.|
Spiders' feet are complex structures; they have to be for the spider to race along her web, or hang on in a windstorm. (Or to hold onto the windshield of my car while I drive; one came home with me like that from Boundary Bay, 25 km away.)
First, the tips of the feet are hairy. But those hairs have "feet", themselves; each one ends in a flat suction cup-like structure, and each cup has its own feet.
The end of each leg is covered with thick brushes of hair, and the end of each hair is covered in tiny microscopic "feet." (From How stuff works.) (Diagram here.)
And then, big enough for my camera to get a glimpse of them, each of the eight feet ends in two toothy claws. (Visible on the foot on the left, above.) If the spider is a web builder, like Brownie, she also has a smaller, third claw, behind these two, which is used to hold a strand of silk and slide along it as she goes. The two toothed claws work for general walking.
|Diagram of web-walker's foot, from microscopy.uk.org.|
So; Brownie got her dinner, a fat sowbug from the smokestack, and she was very excited about it. So much so that she was scrabbling on the wet glass of her box, and not getting anywhere until she decided on a less direct route. Those feet are wonderful, but they don't cling to wet glass!
(More info on spider feet, at Infinite Spider, SpydaWeb, and How Stuff Works.)