Strange red/orange cloud

[flsurfer]

I was looking at my tank and noticed a redish/orange rust-like color cloud that had came out from a piece of our live rock. I looked more closely and saw a fireworm/bristle worm and tried to grab it with tweezers but didnt get it. I noticed the redish cloud coming out of the same live rock a few more times. Our fire shrimp seemed to be interested in the same area that the cloud was coming out from as well.
Does anybody have any suggestions to what this strange cloud could be?
Thanks.

 

[spanko]

Could be detritus it is kicking up, some bristle worms do actually bore into rock so it could be material from that.