So I think my rats might have mites or something, I noticed them each scratching with their back leg and not licking it, they don't scratch all the time, and I don't see any scabs but I guess they could still have them, either from the aspen I used or the new rat from the pet store that was in a separate cage from the mite infected rats, so I need to buy revolution if they have it at my pet store, or is there a place to order it online and ship to Canada ? Is it safe to use on a 4 week old rat ? Do I just put a drop on their fur ? What if they lick it off ? Also can the mites or lice or whatever they have, survive on fleece and carpets ? Do I have to wash everything ?