I'd move them outside, and they may have come from cocoons you included if you used any worm compost to make up the potting soil - I add worms to outside containers because there's always some when I spread the worm bin compost around, but outside if they want to get away they can just go out into the yard - the ones in your house plants are small and sad because redworms are heavy feeders and need an environment rich in organic material - truck'em to the compost :)

Bill