x: freeze dried blood worms are what i call Potato Chips for Bettas. they aren't too healthy.
try getting a variety of pellets. my bettas adore the mix i have. it's mostly New Life Spectrum Grow pellets, which smell REALLY rich, and has a few other kinds i can't remember the name of mixed in. maybe your betta doesn't like the smell of the food. x: smell, is how my white HMPK, Theo, knows where his food is. that, and it's always fed in the same place, but in the beginning, when i first got him, hew searched them out by smell. :3