A:Answer I owned a guinea pig MANY years ago so I'm sure it will pick up its poop as long as it's normal (for a guinea pig) and not diarrhea. The hay is another matter. As you can imagine, it all depends on the length and consistency of the hay. If it's too long or piled too high, almost no household vacuum can take stiff hay in. In this case, if the hay is relatively short (up to 1.5" or so), it should pick it up.