May to June is typically the time when bees will start swarming and it's probably the most exciting time in a beekeeper's year.

Swarming is the process by which a new honey bee colony is formed when the queen bee leaves the colony with a large group of worker bees. In the prime swarm, about 60% of the worker bees leave the original hive location with the old queen. (wikipedia)
And so it happened to me a few days ago. I came out to check on the girls and heard the buzzing in the air. The bees were swarming. Here are some pictures:
the swarm is collecting on the outside of the hive

the air is buzzing like crazy

there are bees everywhere

the swarm soon migrates into a nearby bush

time to prepare a hive box...

...and set a ladder in place

the swarm has landed

carefully clip some branches out of the way

and then just quickly shake them off into a bucket

and finally empty the bucket into the prepared hive box

What an exciting day!
edited: emoji in title; formatting