Re: baby superworm problem?
Could be mold, or something in the air putting off an odor that's mildly toxic to them. I dunno if you're a smoker, but if you were smoking in the room that would kill them. Could be (since you're putting carrots on lids) that they're not able to get to them (little ones at least)... could also be mites. Those suckers will destroy your whole colony if you have them. Check the walls or lids of your bins for very small bugs.
My setup is several 6qt shoebox tubs with whole oats (the quick oats or w/e are bad) and corn meal mixed in. I don't blend anything, because its much easier to have several tubs and move beetles rather than trying to move worms... so I just leave beetles in a tub for 3 weeks, then move them to an empty one. By the time all 4 of my tubs have seen the beetles, the first 2 are big enough to be consolidated, and beetles go into the newly emptied tub. Now that my bearded is brumating I have an excess of worms... so I'm just gonna let my beetles die of old age and then pupate more once she wakes up in the Spring.