Black oil sunflower seed in excess can put on too much fat which can cause egg laying issues by building fat in the abdomen. Other treats are better like an apple or piece of pumpkin. . BOSS once in a while just like cracked corn.Thanks @NanaKat . I was also wondering if there were things I could give them to do that doesn't always involve food. I can tell they are bored because they've been stripping the fluff off of large fallen feathers. They get plenty of protein in their feed and I give them BOSS as a scratch once and sometimes twice a day. They lay well, so I suspect it's boredom more than anything else.
You are wanting them to exercise and move around. A bag of fall leaves dumped in their pen gives them something to scratch thru. You can rake it up several times a day and they will get exercise going at it each time...might put a little treat in there for them to find to kkep them active. Can do the same with a block of straw once in a while. They will find tidbits of wheat.