Hey, that's a great idea! I've got a couple of bags of mouldy chick crumb that would keep a mealworm farm going for ages! I'm just not sure I can be bothered with the hassle.
My other thought was to set up a vermicomposter and feed the excess wurms to the hens. It's wierd though - when we used to keep our hens in a small run, they'd go mad for a juicy earthworm. However, now they are free range, they turn their beaks up at them

. Has anybody else had that problem? (It's lucky our ducks aren't so discerning!

)