Years ago I noticed this activity near Vancouver, B.C. At times in late winter
the bee activity at a feeder was enough to noticably deter smaller bird users of
the feeder. The bees were wading into the loose seed and leaving with pellets on
their corbiculas. Grain dust I supposed.
        A remarkable thing was that the bees actually carried millet seeds from
the feeder to hives 200 ft away, and stored them in cells. When I inspected the
combs, the seeds (maybe a teaspoon in total) would fall out as the combs were
rotated. The seeds were discarded out the entrance and later sprouted at the
foot of the alighting board.
K. Clark