Why would honey bees suddenly occupy hanging bird feeder with bird seed in it?

saw a swarm of bees outside window looked at bird feeder bees inside it and hanging off it 1000's of them. happened very fast.Why?Why would honey bees suddenly occupy hanging bird feeder with bird seed in it?
Honey bees swarm and this is natural behavior, the hive splits with a new Queen and starts a new hive. They will commonly land on things such as branches, bird feeders, picnic benches, and anything that will hold all of them; while scouts look for a good place to start a new hive. they probable won't stay their long, just leave the bees alone and they will move along. They rarely stay more than 24 hours. Hope this helps.