usually pace them in a controlled container..they will eat what you put in the tank and they clean out.
then when preparing them you have a 'clean' source.
you can use worm bedding etc.
I usually lightly squeeze the poo out of the worms..
thier poo is great for the garden BTW.
I try to encourage red worms in the garden no use of pesticides or ferts.
just mulch.
Ok thanks. This worm thing sounds like and entire other hobby!