Since we've moved into the new house, the biggest change we've noticed is in Claire's behavior. She is much more playful and excited now that there is a lot more space for her to run around. Whereas before she was often lethargic and unmotivated to become physically active, Claire now engages in daily romping sessions which consist of nothing more than running back and forth and leaping through the air, usually in 2 consecutive 180-degree turns. It's hard to describe unless you see it.
Another really strange thing she's started doing is nuzzling Megan's hair when Megan is saying her prayers at night. Claire will jump on the bed and start shoving her face into Megan's mane, often gnawing on Megan's head, pawing at the hair, and then eventually laying down on Megan's hair while purring. It only happens after Megan washes her hair, so the popular hypothesis is that Megan's shampoo is obviously made from catnip.
Here's a short video of Claire in action. Notice how 1) Claire chews on Megan's head and 2) the look Claire shoots me at the end. "What? What. I'm not doin' nuthin'."