Nebula once got so excited at a spider on the ceiling, she ran around for 15 minutes going "mew" and being super excited. She then got up on the table and tried to leap up onto of the vertical blinds..she kinda hurt her paw a little bit, licked it and then continued to run around going "mew" and trying to get at the spider at the ceiling.

I've also seen her fall off the computer monitor..she stretched, slid back, and lost her balance.

Also, I left for vacation once, and my friend (she was in charge of makings ure Nebula had water and food) accidently let her out, so my friend was chasing my cat down the sidewalk. Apparently Nebula was excited to be out (she's not allowed outside), but so lonely for people company that she laid down on the sidewalk and was like "oooh pet me pet me pet me". Which meant she was very quickly put back inside...and petted.