Various kinds of Copepods?

[Masterplan75]

Would anyone by chance know what kind of copepod i have in my tanks i know i shoudl supply a picture but i dont have a camera that can get a clear up close picture... they look like mini versions of a mantis shrimp.. kinda long, skinny, crawling around my live rock and i've seen them move kinda like a mantis shrimp where they will be moving forward and then back up into a hole... also i have seen a type of slug / worm at first i thought it was an air bubble but it moves like a slug on the back walls i figured it was just some sort of marine slug... are these good or bad?? i will try to get my camera to work and get some pictures posted but so far have been unsucesssful getting a close up clear picture of one..

thanks..

 

[roka64]

Take a look here:
Xtalreef

 

[majormaz]

Do they have a redish hue?

 

[Masterplan75]

thanks so much it turns out they match identically too

AMPHIPODS

Amphipods are little "bugs" you may see scurrying about your live rock - especially after lights out.
These little critters are beneficial scavengers and are very common. For more info... Amphipods