While I dont disagree with that, I do think that if a small glow engine ingested the amount of grass that a herbivore consumes in even an hour's time, I would say that there are bigger fish to fry.. besides that, steel and chrome are harder than the enamel on a tooth isnt it?? not sure about the aluminum but I wouldnt think that a few blades of grass would hurt anything, perhaps someone has experience that can tell me this is possible?????