How long have you been trying? It took mine 3-4 days to really start grazing at the device. At 1st she didn't touch it. Then she nibbled here and there. Now she is constantly looking in there for food. Lots of people are having great success with LRS Fish Frenzy which is what I use also. And mine just started eating the Masstick today. So that has also been a 3 day process. Even my engineer goby came way out of it's hole to get some left over Masstick, and I never see that guy [emoji23]Hit and miss have the holey tube cbb not eating with it, mastik nope, using black worms to train on mysis but not working yet