The 'black squiggles' are dust that was on the film at the time of exposure, which would have stopped light reaching the film. if it were dust on the negatives at time of scanning they would show as white squiggles. It could easily be dust in the camera, in which case clean the film track with a lightly-moistened cloth or fingertip (but DON'T touch the shutter curtains!) or gently blow it out with a can of Kenair, then clean your camera bag or 'never ready' case.
If the film was bulk-loaded, it's possible that the dust landed on the film during loading. I find it's best to avoid film bulk-loaded by others; it may be cheap but I'd rather have clean negatives - your mileage may vary.
Last edited by kevs; 03-02-2013 at 02:57 PM. Click to view previous post history.