Weird pink shrimp/worms....

Question
I have a 20 gallon saltwater fish tank, and on the one side like about a 1/2 inch underneath the crushed coral there are like mini shrimp things going in and out of the gaps between the crushed shells... you can see them through the glass and there is like a dozen of them and they are pink and honestly do look like shrimp... i have no idea what they are and i noticed them about 3 days ago(when i added a new live rock) and i've had my tank for about 4 months... so if you you can help me on this, it'd be great!!

Thanks!

Answer
Hi Bonnie:  It sounds like you may have an infestation of bristle worms.   You can search google images for some really good photos of them and see if they are close... It may be possible that you have young shrimp in your tank too.  If it is an infestation of bristle worms... there is not much to worry about as they help to keep the tank clean... if their numbers get to be too many then you may wish to try to get rid of them.... keep me posted... dave