Little critters

[rynoe]

Hello everyone. I am new to canreef and the salt water world. I bought a friends established tank and got it moved two weeks ago. Buying this way certainly made for a steep learning curve but other than an open brain that wont eat everything is good. Anyways to my question, tonight I noticed after the lights went out a large amount of little critters running around the sand> they are light in coulour and have little tenticles in front they almost look like a lite almost clear wood bug. Any ideas and are these bad?