Does anyone else's 3 year old caper? DS is driving me potty doing it! He dances around, arms and legs all over the place, tongue hanging out and making noises (kind of singing, but not proper words). We usually let him get on with it, distracting him if it gets too annoying or asking him to be quiet if we're talking or need him to be quiet. It feels like he's been doing it all day long today. It's like his default mechanism if he's got nothing else to do - he'll caper for a bit! 
He also talks a load of nonsense. He's very verbal and can be articulate when he wants to be but he makes up a lot of words. We were drawing a house today and he drew a scribble on it and said it was a "cranky". Sometimes it's hard to get a sensible word out of him. He makes up lots of stories too and doesn't seem to understand the difference between real and pretend.
The silliness is starting to grate a bit and I'm hoping that someone can tell me that it's totally normal and when it'll pass...