I have heard the peepers work, but I don't have experience with them. I would think that the peepers affect their ability to peck the ground and forage, but like I said, I haven't tried them, so that may not be the case. I haven't heard of the anit-pick bits before. Do they fit over the top beak or something? Are all the birds having the problem or just a few? I have heard that protein is sometimes the cause of pecking. I had one hen that had feathers pecked for her back. Between increasing the protein content to the flock and putting a saddle (chicken jacket) on the hen, the problem was solved. Some people have also had success using pine tar.