I watched a spider attack .....
A couple of years ago I saw a spider take another spider on the ceiling in our living room in France. The planning that went into it was astonishing. Up until then I'd had no idea that they could do anything like that. The final bit of the attack was jumping about three inches, grabbing the unsuspecting prey and pulling it off the ceiling so that both were hanging by a cunningly prepared thread. The prey was as big as its attacker, but of course it had no purchase on anything so could do nothing about it and was quickly subdued.
It opens your eyes into what we perceive as intelligence.
The spider looks like one of the smaller species of Theridion (comb-foot spiders). Their web consists of high-tension lines with blobs of glue on the ends that are very weakly anchored to the ground. When something blunders into the thread, it sticks to the thread, but the anchor snaps, the thread recoils, whipping the prey into the air. Result: insect on a string! Otherwise known as a spider's lunch.
I've seen Black Widow spiders (which are in the same spider family) catch scorpions much bigger than themselves in this way.