I think you need another crate just so you know they each have their own spaces... but when we leave the house we use a pen. I DO have two pens, so that Carson and Phoebe are not together, but they see eachother. I left them together once. Carson was about 13-14 weeks old. He wrestled with Phoebe, got a hunk of hair off her hip, and she has never gotten that hair back. She was very tender for weeks. So I worry about them accidentally injuring eachother if I leave them alone together for too long. He was just a tiny, but strong thing. and he doesn't have a mean bone in his body...just a rambunctious baby.
so if you don't want to crate while you are gone.. use pens... I bought mine through Petsmart... here's a link. Worth the money and peace of mind for me!
http://www.petsmart.com/product/inde...amily&keepsr=1
good luck on deciding!
deb