Green worms in my freshwater tank

Question
Hi, I was about to feed my fish last night and I spotted something on the wall of my fish tank, just above the water line. At first I thought it was snail excrement, but it was moving around. After a much closer inspection, I noticed that there are 5-7 tiny green worms. They are about 2-3mm in length. They have a segmented body. They may have tiny legs, or small spike-like protrusions. The head appeared to be black(or a dark grey or brown color) and there was a small portion of a dark substance in the first couple of segments following the head. They were moving around rather fast for their size. The movement was similar to something between a catterpillar/centipede/leech. They did not appear to interact with each other. They were just moving around in figure 8 patterns. They were just about 1/2cm up above the waterline on the glass. They stayed to the moist part of the glass. I pulled one off the glass and held it on my fingertip. It stopped moving. I added some more water to the tank in hopes of them floating down and being eaten by my fish. I do not know if these are normal for a fresh water tank or if they are parasites. I only noticed them yesterday and have never seen anything like this before. I have had this tank for just over a year. In it are some moss plants, a bamboo shoot, two cats and a bamboo shrom with a bunch of snails. I'm attaching links to the macro shots i've taken of the worms on the side of the tank. They are clearly visible as small segmented light green lines against the red. Please let me know if my fish are in danger or if these worms are a normal occurrence in tanks. Thanks so much
http://farm4.static.flickr.com/3201/2985045693_2cf60f2460_o.jpg
http://farm4.static.flickr.com/3050/2985901460_b480b45381_o.jpg

Answer
Hello Vadim:  I would collect as many as those as you can and discard them.  I would also watch the tank closely for any signs of those worms... if you see them on the fish, etc I would treat the tank with flukes tablets... They look like something akin to an anchor worm.... and that would not be good for your tank.  If you use the fluke meds take the snails and catfish out of the tank.  dave