You are feeding actual pellets, bsms - as in that is what it says on the bag? I ask because, yes, there is different sizes. There are those marked as "pellets" and those marked as "cubes". Cubes are considerably larger -- imagine 1 1/2x 1 1/2 (or maybe 2x2) square and, whole, about 3-4 inches long. The alf/grass content is a much coarser chop than you find in the pellets and they are packed tight and solid, like long, square rocks for lack of a better description. Basically, they look like a HARD, green stick of butter is the best comparison I can come up with.