I feed the large ones to my african bullfrog. My monitor lizard is so big it would just ignor the worm. But you know how Pacman and Pyxie frogs are towards worms! Oh a layer of leaves on top that is kept drier than the substrate will help keep the worms from trying to escape as much. I don't have a problem with Canadians ever escaping but the other ones like to try.

worm whisperer haha! I've only been at it since this summer! With 250 Canadians, you'll have more than enough experience soon to enlighten the rest of us about how to best keep them.