apparently this is not new and this food is also called osmocote i have seen it mentioned in posts as far back as 2008, wonder why I haven't come across it. The osmocote I am used to is orange and in pellet form. sorry for any confusion. Someone on another site told me that the fluid filled balls probably vary in size because the bigger ones probably have a thicker shell but contain the same amount of liquid which would cause them to open at different times.