poop bags to. I used to sorta hate using them as I use the grocery bags for it along as little trash bags (although they get tied up and thrown into a bigger trash back when full). The poop bag rolls are just to good to make sure you never are without a bag (you need to have two attached to your leash sho you can refill one after its out while useing the other). Could say cat litter although you could debate you use it for a purpose first but then again you can say that about poop bags and ultimately trash bags. Its purpose being collecting the trash in one location before disposal.