Worm Like Creatures

[tlk]

After the lights go out, I have a bunch of worm like creatures that come out from who know where. They are between .25 and 1/2 inches long and gray/black in color. Some also look like anorexic potato bugs. They run around on the floor of the tank. Anyone know what they are, how they got there and what they are doing?

 

[bang guy]

Can you describe them in more detail? I have a difficult time envisioning a worm running around.
Can you see them feed? How and how fast do they move.

 

[tlk]

They only come out at night. I will try to get a picture of them tonight.

 

[tlk]

Here are the "worms". The one in this pic is around 1/2 inch long. As soon as I turn on the lights, they start heading for the rocks. Any ideas would be appreciated.

 

[tlk]

These two are around 1/4 inch in length

 

[tlk]

another that is around 1/4 inch. They only come out at night and run for cover as soon as the lights are on. I also don't see them in the morning before the lights are turned on. Any thoughts would be appreciated.
Thanks!