Question about my Hippo Tang...

[Animal-Chin]

So back in January I adopted a Hippo Tang. It's about 3 inches so its still a baby.

Put it in my display and it seemed really healthy. Eats like a horse and eats anything I feed it. Very active and just a cool fish all around.

About a week in, I see some small bumps on its side and think "oh man here is ich" but it only is like 3 spots and they aren't white, just small grain sized bumps on its side. A day later, gone...

Now over the last 3 months, about every 3rd day it gets a few of these spots. Just a1 or 2 or 3 and then they are gone the next day. The fish is FAT as I over feed and he's getting bigger and bigger. Really healthy.

NONE of my other fish have shows a spot at all.

Leads me to believe its not ich? Now every night it sleeps in my green slimmer acro, could it be getting small stings from the coral?

Just sort of at a loss about whether or not I should even be concerned, thoughts?