Oh, my! This is hilarious! I remember people talking about this guy who did an obstacle course for squirrels. I don't think I ever had a chance to witness squirrels doing such things in Russia, but in the US they are just... everywhere! and they are crazy!.. Now I hate squirrels. I have a personal war with them. They killed a small oak-tree I planted and some of the flowers, like tulips and they also wake me up at night, because they get into my attic and start scratching there. They keep attacking our bird-feeders, spill the grain and scare the birds. My dog loves hunting them in our backyard. Once I managed to let him out silently enough that he almost caught it, they rolled in a ball together, but the squirrel slipped away... We caught two squirrels in my attic with a mousetrap and the third one with a rattrap, and I had to carry it out with a triumph.
They are nice in the forest and its fun to watch them preform their acrobatic skills on the feeders, but they are just evil sometimes... 
Also at war with squirrels here, with the extra bonus that they're not even native to the island of Newfoundland! After the last glaciation, they weren't able to recolonize (because island), but then some genius brought them here, possibly with the notion that they would keep the hemlock looper (a forest pest insect) down, which of course they don't. Our cats have a "catio":
On the right you can see the tunnel to the house, where they have a cat door. Despite presumably reeking of cat (one of them would rather do his business out there than in a litter box) the squirrels go in, and several have paid the ultimate price for their trespassing. Others have been released alive in the house, presumably to train us in squirrel-hunting, which leads to a thrilling game of chase (with excited cats underfoot) as we try to corral and eject them.
Where we lived before, we had outdoor cats. One of them spent a winter sitting in the window watching a squirrel that had made a tunnel under the snow from a tree to the bird feeder. She would sit there glaring and twitching her tail, and we figured she was saying, "Just you wait... first nice day in spring when the snow melts, you are TOAST!" My SO nicknamed the squirrel "Purina", after the brand of pet food. Sure enough, I came home on the first nice day of spring, and there on the kitchen mat was Purina, lying flat on his back (it was
clearly a he), not a mark on him. Man, that cat was one amazing hunter!
