Looks like he's confused by the tufts on his feet and is trying to get away from them 
Does he do it anywhere else? Maybe they stand out more to him against the flat uniform wooden boards of the deck, vs. out on the grass against a more textured natural surface, and they look different to him. Or maybe he has finally realized that chickens aren't supposed to have feathers on their feet and is outraged... "What have you vain people bred us to look like??" 
Does he do it anywhere else? Maybe they stand out more to him against the flat uniform wooden boards of the deck, vs. out on the grass against a more textured natural surface, and they look different to him. Or maybe he has finally realized that chickens aren't supposed to have feathers on their feet and is outraged... "What have you vain people bred us to look like??" 
That's why I zoomed in on his foot at one point in the video because I thought maybe something was stuck on it or wrong with it. I actually brought him inside and did a close inspection and washed them. One toe on his right foot is a bit deformed but it was his left foot he seemed to be looking at. He's such a silly guy.
