yup, like fishman said, you should be able to see them going in and out of your rocks. pretty cool stuff. Also, when your lights are off, they are more adventurous and come out onto the sand. so when you flick em back on, you should see scurrying all over the place. If you have a mag float, or any algae scrubber that sticks on the inside of the tank, you can also see copepods in between the two parts.