Weird Sounds Inside the Beehive

Occurred on May 29, 2019 / Lowder, Illinois. USA

Info from Licensor: "This video was edited from clips I recorded over a couple of years. It's about a strange sound coming from a couple of beehives that, as far as I have found, no one knows for sure what it is or how it's made.
What makes this sound inside of a honeybee hive? In May 2019 and again in August 2020 I heard and recorded a loud "growling" sound coming from 2 different hives. Only a few people have ever heard it and no one seems to know anything about, including scientists in bee labs. Among the many unusual things honeybees do, this could be the most unusual. Certainly the least known or understood. Some have suggested the sound is made by queens, but I've included video of queens "piping" and "quacking" in contrast to the growling sound. What do you think it is?"