Sherri, they are most active at night and you can easily see them moving in the early morning, just as the sun comes up or lights come on.

I have gone the natural method since they don't hurt anything and are hardly noticable anyway. They seem to eventually dissappear. Things are doing well, so I am not adding toxins to the tank anymore. Less intervention. I gotta agree with that. The less I add of things other than a few trace elements, the better it seems to work out.