Here is a technique that I learned from Grampa Maves..
He buries an old cooler on the north end of his house so the top is level with the top of the ground…
He drills holes in the bottom of it and then put a screen over the holes…. he puts in wet newspapers, leaves and a little black dirt, coffee ground or whatever else organic food he finds and when he picks crwlers he puts them in the cooler.,…. works great all summer if it gets to a dry spell in the weather he just puts the hose to them for a spell and they get all the moisture they need and stay cool enough…
I just used a plasic bucket….but things to remember when you are digging the whole…. put a layer of rocks in the bottom of the whole before you fill the dirt in on the sides and even a layer of sand wouldn;t be bad…. this keeps the cooler or bucket from filling with water and drowning your crawlers..
also make sure you punch holes on the top of the cooler or if you are gonna use a bucket make a lid with holes….. you need a lid if you have skunks, coons, slamanders, etc,,, that like to get a free lunch….
This outdoor method works great if you gotta good spot to do it and the wife won’t freak out about the worms in the house…. They really do stay along time… even in the fall he would cover it with a little straw and continue to use it until the crwlers were used up….. hope this helps