Some queens love to move their babies around so as not to let the enemy know where they are ... their scent gives them away you see so they cannot be allowed to let the scent build up. You and I cannot smell it but they can. As has been suggested, try making a new nest.
When Suki did this with her babies, I humoured her for a bit, changing all the bedding for fresh clean blankets in a different kitten bed in another secluded area. Just followed her with the kitten in her mouth and when she placed it - of course under a bed in a cold corner - I just lifted it up and put it in a prepared bed in a warmer area near a radiator in my bedroom.
Hope they are all doing well.
