I got 2 guninea pigs now and the only noise my bigger one will make is like a purring noise and the only one my white one will make is like a "WHEEK" noise. Why is this? i see them running around teh cage and "jumping" and i've had them together for going on 2 months now and they seem to really like each other =) but my big one that is just a couple months older seems to be dominant but they have never fought.