Yesterday I woke up to find several hundred bees flying all over my yard, and some of them were attacking my hummingbird feeder and some leftover hummingbird nectar that I forgot to take back in the house. They were very un-aggressive, so I left them alone, they finished all the left-over nectar and went away when the sun went down. This morning there they were again, all over the hummingbird feeder. This hasn't ever happened before that I can remember. They did not form a swarm, they were just flying around and competing for the food source. Might they be part of a swarm that has lost their queen, and just looking for food sources until they find another hive? I'm happy to see them, but I'm worried about them.