Coral eating Crabs

So I noticed a couple of my acro colonies weren't looking to good the last couple weeks. All my params were perfect, I run AI's so i knew it wasn't a bulb issue. Then yesterday I noticed a tiny little crab on one of my colonies and figured he was a good acro crab so I left him alone.
Today I came home and noticed another one on my blue tricolor Valida that has been showing polyp retention and lighter colors recently. I put two and two together and investigated the crabs a little closer and noticed they had a little fuzz on them. That was a dead give away, Oh and the fact a big chunk was missing out of a branch on my purple acro colony and I saw him munching away at the flesh.
I grabbed the tweezers and after 15 minutes of playing tag with them i finally caught both of them. I put them in my nano angler tank for now so I can study them for a while. I'll try and get some pics sometime but they are small, like half the size of a pencil eraser small. I feel so relieved knowing why my favorite pieces were starting to go down hill on me. I didn't think anything of it at first because I have two little crabs that HH in my pink birds nest colony and have been living there for over a year with no ill effects.
So if you notice one of your favorite corals starting to slip away on you, keep a close eye out for these little bastards.

 

Yeah they have a little fuzz, reddish color and white or light blue eyes.