This is quite normal. Piggies are not "pigs" and will only eat as much as they need, they will not "pig out". Th rest of the time, they will sleep and poop! And if they are very young they will spend a lot of time running about, if they have the space. Please tell us more about them. How old are they, boys or girls? Where did you get them, what breeds and colours are they? What are they living in, hutch or cage? Post some pics if you can.