I think anything could be considered a treat! lol. Anything I feed my chickens by hand is a special treat to them it seems. They can be in a yard full of grass, but if I pull up a handful and feed it to them, its like the tastiest thing they've ever eaten! LMAO. I too would give the roo a chance to come around. I tried dominating one of my problem roos by scaring him but didnt feel good about it. And it seemed to make him trust me less. The opposite of what I really wanted. I get a little peck once in a while but nothing hard, I would try picking him up when he does it and carry him around a bit. I think he's young and unsure of things and asserting himself out of fear and distrust. I am by no means an expert, but I have been successful so far. I often hand feed my roos treats (literally anything you'd eat) and they in turn give them to the girls. I would not chase the roo personally, but I am not afraid of him and wouldnt let him run me off either.