Randy, I had the same impression about some eggs not hatching before, but I was surprised several days later to see tiny larvae. You probably wouldn't have seen them without magnification. The best thing to do is to put the cardboard with the eggs in your container (but not in the food) and leave them.
I would keep the colony shaded, but a hot sunny day will be when the adults are most active. If you aren't seeing adults yet then definitely let the mature larvae go. I would place them on loose soil so they can dig in before toads and birds get them. I set aside some prepupal larvae a few days ago and I'll let you know when they start to emerge. You can follow the progress at my blog if you want to.
I'm collecting more eggs and I'll send them to you in a few days if you're interested. In the future I think I'll send people a combination of eggs and pupae or final stage larvae (prepupae). I think that would be an effective way to seed an area.
Thanks for the report, still no word on the BioPods yet.
edit: I'll bet the larvae you found in the box hatched during shipment and got out of the plastic bag. I think that would explain how larvae got into the box.
