Are they all white in color? I used to have blood worms in my tank. They would drop and dig into substrate when I fed my fish and then they just multiplied.. I put a fire eel thingy in my tank and that got rid of most them. I redone the substrate to remove them all and now I don't feed worms anymore lol. My worms were reddish and sometimes white..
However they might be Planaria worms. If that's be case I would redo substrate personally for peace of mind.
However they might be Planaria worms. If that's be case I would redo substrate personally for peace of mind.