What could be doing this?

[Cheese Eyeball]

My orange montipora digitata frag has been doing fine in the last month since picking it up at a frag swap.
This last week I noticed areas that initially I thought were the result of bleaching, since I had ramped up the LEDs another 15-20%.
But upon closer inspection I believe this May be caused by another tank inhabitant.
That hole is the most telling thing to me.
I was thinking maybe one of the blue leg hermits, but I'm not sure.
Any thoughts?

Ed

 

[Cheese Eyeball]

Forgot to add the picture

 

[PaleHorse]

bugs maybe

 

[Felixc395]

Check for nudibranchs yet? They can really go to town on montipora quickly. Is the picture accurate because even the non-recessed flesh looks a little upset. How was it when you picked it up at the swap?

 

[PaleRider]

i did the bayer dip. it will kill them without hurting the coral

 

[Cheese Eyeball]

The frag was in pristine condition when I got it about a month or two ago.
It in the past couple of weeks I had noticed it was starting to encrust the frag disk, and the color was really good.
The picture i took this morning was with the lights off.