My guinea pigs don't have fleas, at least as I can tell, but my dog has had problems with fleas in the past. I noticed one of my guinea pigs scratching and for some reason I was just worried that she might have gotten fleas. I checked her and my other guinea pigs and I don't see anything. My dog doesn't have any right now either so it is unlikely that they would have caught fleas from the dog. I am just being overprotective and I always worry about nothing, but I am wondering if I can use diatomaceous earth if my guinea do get fleas in the future. As I have been researching it, some sites say not to use it because it could cause respiratory problems because of their small noses. But a lot of other sites say its perfectly safe for them. Sorry if this is a stupid question.