Why does my baby always rotate her wrists

She's always rotating her wrists back and forth / flapping her hands and opening and closing her hands or bouncing her arms up and down. Is this normal? I mean she's doing it whenever she's not holding a toy or when she's holding a toy she does it with the toy. I guess she just has a lot of energy?? Everything else w her is completely normal aside from her weird grunts when she's excited too lol