White worm things? Help!?

Ok, I'm my 10 gal tank, the are like these white worm like little things, like alot all over the glass, are those bad? Tube been there for like a week, if I look really close and hard, I can see them moving. Wat are they? Are they bad? Do I have to get stuff to treat it? Wat stuff to treAt them? I think that they go from kettle fuzzies to worm like catiplilar things. If I'm worried about it spreading to my other tanks, and I have to treat it, would it be bad if I treated the tank for them even if they didn't have it?