The new nuc we received on Saturday had approximately 20% dead. We poured them out of the box. Today we saw an assault on the hive, with all comb being opened, whether honey or larve. The wreckage was all over the frames, and as I opened the hive we saw the young larve at the bottom of the screen board. Has anyone else had this type experiencE. I will try and attach pictures.
Its not unusual to see a dozen larvae dragged out of the colony after falling to the floor or being removed from cells by nurse bees at any time of colony growth. That's hygienic behavior and there are tests that measure hygienic behavior in colonies since its a desired trait. In my experience many things can result in 20% and more of a colony ending up dead, starting from simple to more complex - 1) temperature swings or ventilation - air (too hot, too cold) resulting in larvae mortality, also referred to as brood chilling, too doggone hot or not enough air, 2) food and water availability, 3) pesticide exposure (or other substances), 4) pathologic bacteria brought in by foraging bees, 5) viral disease brought in by vectors (mites, beetles, roaches, bees, etc.) I would suggest reaching out to an experienced club member near you to take a look, while following distance and protective equipment recommendations by the local health department to keep you healthy. If that does not satisfy you, local inspector may be the person to call.