Funny insects on my indoor plants

Got funny almost transparent little worm things - 1 cm long or smaller - can hardly see them - living in the damp soil of some house plants / seedlings on kitchen windowsill.
Anybody have any idea of what these could be and how I can kill them without hurting the plants (mainly herbs).
Thanks
Lissy

 

I think they are the lava of fungus gnats, they are encouraged by the surface of the compost not drying out between waterings. They feed on the compost itself and not the plants, they develop into small black flies that in turn lay more eggs.
If you dont want to use chemicals, you could try allowing the compost to dry out a bit more, and watering from the bottom.

 

that explains a lot - have had some black, like midget flies around.
Thanks - will not water so much and see wot happens
thanks again