WoW... never saw that before! The manure balls in the original vid. Never even imagined such.
But about chickens being stupid - really not so...
I have a small flock of rescued "egg" hens. They are very clever about choosing where to dust bathe, always liking the area where the sun will be in the next half hour - AFTER they've dug into the cool dirt. They also have great memories and can identify up to 50 members in their flock. And they certainly recognize their care-givers above strangers. They have a wide range of vocalizations, about 25 or so, that communicate predator, food, friend, etc. They can be taught "tricks" and have a memory for "reward". For instance the hen I call Buffy is a theif - and will snatch nearly anything she can drag out of your hand and "hide" it from the others... Eunice likes to glide to and fro the yard... I guess she's amazed she can fly(?) Liz will come when called... I can't even get my dog to do that half the time.
Another likes pushing a tennis ball with her beak.
All this indicates "intellegence" and awareness.
So, chickens are hardly automatons or even "stupid". It's just sad we've allowed ourselves the indoctrination of considering them "birdbrains". Everyone I know who has socialized with them, walk away with a totally different concept of what chicken personalities are really all about. Chickens, and birds in general are pretty cool once you get to know them... really.