Nothing is normal except the absence of normality. There is variability in everything. The bees in the frame feeder are either really trying to get to the food or they put some comb in there and the queen moved in.
I'd let it go completely dry and if it is still full of bees then, most likely, there is some comb w/ brood in there.
I'd let it go completely dry and if it is still full of bees then, most likely, there is some comb w/ brood in there.