Back when we had reptiles we used to raise mealworms. They smell _awful_, but are insanely easy to raise.
Warning: Mealworms that are swallowed whole _can_ chew their way through reptile stomachs and bird crops. It doesn't happen often, but it does happen. We got around this by pinches the heads with tweasers. For a while the body wriggles around but there's no risk to the animal.
If you want to raise bird/fish food I highly recommend African Crickets. They're painfully easy to raise, are risk free and make great bait. I'm also trying out red worms to see what I can do with those. I doubt we'll bother with mealworms again.