[Roady]

I recently purchased a valentine puffer. It has been in the tank for about a week now and seems to be doing fine. The only thing is I've noticed some odd behavior from him. I've read that they are a nocturnal fish. I woke up this morning and noticed that he had placed himself in the edge of my tank at the top of the water line, and then later on today while i was watching him he spit up some stuff randomly. He also likes to attack my hawaiian feather duster. Is that to be expected? I was also wondering if anyone knew or had any experience with how these fish behave. Any info you would great or if anyone knows where I could read about different types of fish behavior that would be great too. O and what is the best thing to feed them?
Here are some pics of the little guy

[snapper1]

That is odd behavior I have one with my Niger Triggers and have never seen that before.I would watch him closely so he does not go postal is he with other Fish.