I once fed one of those, with a raisin, hastily pulled out of my müsli, and put it on the tip of a long needle.

Did a nap at around 2 to 3PM on a sunny day, had the balcony door tilted inwards.

Got woken up by a strange, and rather loud buzzing sound, maybe like when you're holding a strip of paper, or soft plastic into a ventilator/fan.

Searched and saw nothing at first, until I saw movement behind the lowered window blinds.

Pulled them back and made that hornet bouncing against the glass, like panicked.

Put them back very slowly, raised the blinds of the balcony door and opened it wide.

Tried to shoo the hornet towards the now wide opened balcony door by slowly pulling the blinds back wide. Didn't work. It just bounced against the glass even more panicked.

Put the blinds back very slowly again.

I somehow got the idea that I maybe should give her something to eat.

But what? Honey on a spoon? Sugar dissolved in water? For whichever reason I decided to pick a raisin out of my müsli-box, and put that on the top of a long needle.

Don't ask me why. I never did that before, I just came to me. I can't explain how.

Anyway, I held the needle, maybe 10cm long, glinting silvery, very slowly and steady between the gap of blinds and windowframe, and the hornet crawled towards the tip on the inside of the blinds, tilted by 90°, like crawling on a wall.

And it began to gnaw on the raisin! I could see it shrink, took maybe 5 minutes until it was gone. Pulled the now empty needle back very slowly, and waited.

Hornet did something like 'aerobics', a strange dance, while still sitting rotated by 90° on the inside of the blinds, raising one of her legs at a time, grooming herself, and its wings. But rhythmically, several times.

For maybe two minutes.

Then, without bumping into anything, it flew out of the gap, and made two slow circles of maybe half a meter in diameter, maybe half a meter away from the tip of my nose, or my eyes, counterclockwise.

Absolutely coordinated. No variation in speed, and the circles like being drawn with a pair of compasses.

For maybe half a minute, max.

I stood very, very still.

And then it buzzed out very fast through the wide opened balcony door, in a straight line, out of sight.

I stood there, wondering, did that really happen? Am I still dreaming?

WTF?!

That was one of the stranger things happening in my life.

Unforgettable :-)

You do know that they communicate via these movements? It was signaling to others that food was here.

https://en.wikipedia.org/wiki/Waggle_dance