If you see a ball of bees like this in your yard this Spring – in your bushes or trees, on a fence post, etc. – leave it alone and please don’t try to destroy them. It’s called a bivouac.
A bivouac is an intermediate step in the process to bees take to find a new home. They leave their existing hive, bivouac while they search for new digs, then fly away once they find a suitable spot. It usually only takes a few hours, a day or two at the most.
Are they dangerous? Will they sting me?
When bees bivouac, they are extremely vulnerable and docile. Their only concern is finding a new hive location. They could not care less about you and, as mentioned, they will be gone soon. Unless you have an allergy, you can even get pretty close and look. It’s fascinating, if a little unnerving.
I want them gone now!
If they’re really just creeping you out, call a local beekeeper and they should gladly come remove and re-home them.
If you’re really a nerd for this stuff, there’s a great book on the science behind the bivouac called Honeybee Democracy by Thomas D. Seeley.
To me, a honeybee bivouac is a wonder and a privilege to see. Enjoy it!