What size tank do you have. I have 15 in a 200 gal and they do that all the time. They get picky but they do eat it if I leave it in there long enough. I go from frozen to live and back. Some times they just get jumpy. How old are they? Have they started to turn black? Mine get real jumpy when they are breeding. If hey don't eat in a week or two then I'd worry. I feed mine about every 5 days. They have been good for 2 years now. I just had 4 more spawnings the other day.
Good luck
Good luck
) that I had a problem with them nipping and fighting a lot and the answer i got there was to bacically keep them well fed. 