They have been pretty mellow so far. I imagine they'll get wilder, though, as they get more accustomed to it. So far they have been most active at night, chasing after each other, knocking things over, being really noisy. They sleep A LOT during the day. At night we are putting them back in the kitty room. Maybe they'll stay contented in the pen just long enough that they aren't spooked by every little noise they hear down here. I just want them to acclimate to this part of the house. It's bigger, noisier, much more active. When we've had them down here before, their run and hide instincts kicked in and we had to search for them. It took hours to find them! Going slowly this time, and expanding their world bit by bit. Hopefully it will work!