my friend gave me some live rock about a week ago. i was looking at it today and noticed that there are these little translucent brown/green bugs crawling around on it. i assume that this is normal but figured i'd ask. are any of these harmful to fish? they're about 1-2mm in length. i'd take a picture but they are just too small. they don't swim in the water -- they seem to just stay on the rock.
You can also ask your LFS for some of the sludge out of the bottom of their curing tank. It will be loaded with all kinds of little critters. I have done that several times. Another way is to trade sand with a fellow reefer.