Who’s drilling in my live rock

[shooter2377]

Ok, so I got some live rock a while back and recently noticed that something is burrowing straight in to the rock, as evidenced by the pile of rock dust. (The gray in the picture) It looks like there are maybe some pickers or something sticking out of the live rock, but when touched don’t really seem to react. I’ll look later when the light are off to see if I can see anything

 

[fcmatt]

Not much in our tanks can drill into rock. It was probably a soft spot in the rock breaking down naturally.

 

[shooter2377]

Some more pics

 

[shooter2377]

Any ideas on this?

 

[ArnoldosAquariums]

…boring clams?

 

[NowGlazeIT]