When I got my first 4 ropes I had to break up the carnivore pellets for them to eat them. Just like you are saying they'd mouth them but wouldnt eat them. Problem was the size, it smelled like food was just to much work to eat them. I tried breaking them in half that was still to big. Thirds seemed perfect. My ropes we're small two were less the 8" more like strings then ropes. It took my fish awhile to eat the bug bites but now all of them eat it and go nuts when I put some in the tank the small size would be perfect. Even my bigger polys search those out now too. They are hard at first but soften quickly and the ropes love them once they soften a bit. Tilapia tilapia tilapia tilapia....