Regarding the above post where you noticed the worms in the oat bran are lying on top. I've read that worms will do that when there's a mite infestation. Look very closely to the lid and sides of that container. If you see what appears to be white 'dust', look even closer. If they're moving, they're mites.
I heated all my bran in the oven before giving it to the mealworms. I just think it is the fine texture of the bran might make it a little more dense then they are used to. Thanks for the tip though