Red Wigglers (manure worms) will eat the scraps and shredded paper much faster than the night crawlers. The night crawlers like to go deeper (3 ft) on occasion and would probably leave a shallow container. If the red wigglers are happy and fed right with the correct soil moisture they will get big and fat and tend to loose some of that dark red color and as catmandoo said, and turn more yellow on their bellies.
I have my worms in an old water tank. I mix in table scraps, green cuttings and manure from my neighbors horses and chickens. A few citrus peels wont hurt but dont over do it. Crushed egg shells keep your pH in check as well. Avoid any meats. Covers on top with aeration on the sides keeps flies and pests out of your bins.
They will die if you dont feed them or change or at least dilute the castings in the soil. If you add the shredded paper as mentioned 2-3 times a year you will have no problems. The castings are better than any commercial fertilizer made and it is not "Hot".
