I'd like to add another caution about pets eating stringlike objects. When I get done flossing my teeth I take the floss and double it up several times and tie it in a double knot to make a compact package before discarding it. The pets like to investigate what's in the trash can, and I'm sure the floss retains aromas that interest them. It's not the fact that it's string that causes stomach/intestinal damage, but if it's of sufficient length to get wadded up into a ball too big to pass, or cause problems as its length meanders and gets caught along the loops and turns of the bowel causing constrictions.