(By the way, Daisy is the tan ratty. Petey-Pie is the gray one.)
They have a plastic coffee can hanging in their cage, and I cut a little hole in the lid so they could crawl in there and it would be a nice cozy little nest box for them.
So the other day I gave my little ratty bratties a cardboard toilet paper tube to play with/chew on, and last night there was a bunch of ruckus going on in their cage.
When I turned to look, Daisy was attempting to hoist the toilet paper tube up through the hole in the coffee can so she could take it into her nest with her (and presumably keep it away from Petey-Pie).
Unfortunately, she kept dropping the tube, at which point it would tumble down to the bottom of the cage and she'd have to go retrieve it (before Petey-Pie got to it) and haul it back up to the top shelf and repeat the process.
I watched Daisy do this several times, and then I saw a tiny little light bulb go off in her tiny little head.
She proceeded to stand the toilet paper tube up on it's end so that it was closer to the coffee can. She then climbed into the coffee can, leaned out, grabbed the toilet paper tube, and hauled it inside!
It was so amazing! It really was. Who knew that rats can problem solve? Now let's see you show me a frickin' gerbil that can do that. I don't think so. Unfortunately, by the time I realized what was happening, it was already over so I couldn't take pictures/video. Boo. But it was seriously awesome. Seriously.