I've read about bees gathering dust from bird feeders in the spring but not when there is pollen and nectar available. They usually stop once pollen is available. The birds should come back. Maybe you need to wash/clean the feeder real good--maybe there is something from the manufacturing process (I'm assuming you bought the feeder) that is attracting the bees.
Welcome to BeeSource by the way. You'll find answers and discussion on just about anything "bee related."
Welcome to BeeSource by the way. You'll find answers and discussion on just about anything "bee related."