pest, parasite,neither?

Question
Hi, I have noticed small, dark worms approx. the size of mosquito larva crawling above the waterline in my 10 gal. In the water, there are a few more: small, white threadlike ones that seem to be immature versions. I can stir them up from the gravel.  They have been there for about 2 wks., as far as I know, and my 3 fish( pastel tetras and algae eater) don't seem any less healthy.  I haven't noticed any changes.  There is a thriving bulb plant( water onion ?) , and there had been some plastic plants I'd removed about 2 1/2 wks ago( they developed whitish,slimy,areas of gunk that I suspected grew after keeping dormant on the plants when they were stored after being used in same tank w/same fish). Any clues?

Answer
They could very well be mosquito larvae I'd suggest you do a water change and get rid of the water before you end up with bugs in your house that you don't want there.  If you do a complete water change and get a product that is sold called 'Cycle' and use it according to directions and you should be ok. Too bad the fish won't eat them O_o.