Why is my fish darting around?

Just a minute ago I was feeding my betta fish, Mozzorella and he was darting around the bowl. I have had him for a while now and I have never seen him do that. He is always floating at the bottom, he is alive but just half floating. My mom thinks that he was sick, but I think it's unusual. Also after he was darting around he fell to the bottom like usual, and stood up-floated, like he usually does. I just want to know if I should be concerned about the darting or maybe it's just normal.