I've had some of my teenage roos do the same thing yours did , but mostly they peck and try to grab on like a bite like some roosters do to their hens to hold on. I just keep on and pick them up and carry them around like a baby doll, baby talking and petting their necks and face, and it usually breaks them of it when they get treated like a little baby doll, because I only let them go when I'm ready- not necessarily when they're ready. They end up realizing I'm not trying to hurt them and that I'm in charge. Some that have done that have still turned out to be the sweetest most tame pettable roos. I had one Houdan, that would peck my shoes every time he wanted to be picked up, and once he was in my arms was as happy as could be. He started off as a skittish chick I'd bought after he was a few weeks old, but I had to rehome him d/t my 'mean hens' picking out his crest. I don't know if this would work with older roosters though.