Ah yes, that is very normal behavior.....bettas are opportunistic feeders, they don't have that "I'm full I need to stop eating" switch in their little heads....so they always appear 'hungry'.
You know, I had that trouble as well with Omgea One pellets....at the time I had about nine fish, and every single one of them turned their noses up at it. With all the great reviews on he brand I thought maybe I just ended up with a bad batch....though maybe it wasn't just me!
New Life Spectrum, however, I have had FANTASTIC success with....and its the best out of the two anyway. xD After struggling with one of my boys, trying to get him to eat for over two weeks, I was finally able to get him to chow down on NLS. I would highly recommend picking up some of that.