Does anyone else's babies have mood swings? Hot Rod seems to have woken up in a mood today!

Normally he is a slow waker-upper-r but today he was ready to go. He is growling at nothing outside and will only eat if I feed him by hand! I don't think it is anything physical, I think he just woke up on the wrong side of bed. He is normally a sweet little guy and always ready to be held and gives lots of kisses! Just one of those days I guess.