These birch logs are free any nasty pesticides or chemicals, and have holes drilled in to them so you can stuff them with herbs, hay, even safe flowers! Birch is a great chewing wood for small animals. A busy beastie is a well-behaved beastie! Note: the "stuffing" is just a serving suggestion, but isn't included. Sorry...but we've got lots of healthy options! (Take a look at our Herbal Blends for some fantastic fillers) Two sizes, so they fit everyone.