I've been trying to get my quaker and cockatiel to eat pellets, and I'm about to run out. They've started nibbling on them when offered by hand, but it doesn't seem like they eat it very much when it's in the bowl with their seed. Should I try buying them a different brand of pellets, or should I stick with the kind that I've been using for about 2 months? I've been giving them Roudybush.