That and they are always available. Nothing special needed....just a decent size tote with a lid. Drill tiny holes everywhere and your done. Grab some paper , rip it up, soak it in water for a minute, wring it out so its not dripping wet , put that in the bottom of the tote, add table scraps and a handful of dirt , then top off with more paper.....your up and running. Very very simple. If the worms try to leave then somwething is wrong in the bin. (too much moisture , too dry , not enough food ect...)
You can leave them be for months at a time if you really have to.