Help, sick fish maybe?

[Llamarama]

I can only speak for the GSPs as I have 2 but I know mine turn black based on mood it seems as the water parameters are consistent but I also notice my puffers often shove themselves between the rocks as well as between the filter intake and the glass looks like fun to me and I've had them about a year and I'm positive they're not sick. How old are your puffers? Once they reach about 2 or 3 inches they don't need to be fed every day either