When playing in my normal world, I created an enclosure for my armadillo with hoppers on the floor to collect his scales without having to use too many brushes. But after an hour and a half of playing, I realized that it generated a lot of scales, almost a pack and a half. I don't know if it's a bug or the default setting, but it would be nice if the mob dropped fewer items to make better use of the brushing mechanic.