Strange Worm/bug In Tank

[nitrochicken]

Hi,
Noticed a strange worm thing moving around on the glass of my aquarium today. Found a couple of smaller ones now too.
Any ideas what they are and do I need to be worried?

The largest one is only about 5mm long and very thin. The middle part is slightly fatter and it has a round head.
Here's the best pic I could get using my camera and a magnifying glass:

Dale

 

[col748]

I don't know what it is but unless you want "strange worm/bug thing" in your tank i would get it out.

 

[TylerFerretLord]

Is it flat on the glass or is one end stuck to the glass while the rest sticks out into the water?

 

[nitrochicken]

Its flat on the glass and moving around