In case you’re wondering how smart rats can be, and if Ratatouille is real, then allow me to share this story: I once had two rats, River and Chell, both rescued from a laboratory as babies. Chell was whip-smart and liked to ride around on my shoulders as I walked around the apartment. She would recognize places she wanted to go, such as her cage or the sofa, and I would raise my arm up to let her run across to her objective. She quickly cottoned on to this and, in an entirely self-taught behavior, would run to one of my shoulders or another and tug on my sleeve, to signal me to raise my arm in the direction she wanted. In this manner she was able to steer me around the apartment and would frequently use me as a taxi instead of walking herself. She then taught her sister how to do it too.