I would initially let them all have floor time together but keep an eye on them. If they start to growl, then separate them. I piggie sat last week for 4. (I already have 4) and also have a small apartment. It was crowded but everyone (especially me) got along. Sandi Korman VIP/Axces Systems Division ph: 516 333 8585 x 14 fax: 516 338 0894