I've had my betta for a little less than a week now and whenever I put food in his tank (three pellets once a day) he acts hungry and goes to eat it, but then spits it out. Sometimes he'll keep trying and finally eat a pellet or two. They're Wardley's betta pellets. Is this normal? Should I try a different type of food? I've read they like blood worms, but that it should only be a treat every once in a while. I'm really worried about my fish!