Has anyone ever heard a colony “purring” (instead of humming) when you stand outside the hive and listen? I’m perplexed.
I’ll post a little background once I get a few initial responses if anyone has heard something like this. The background might give a bum steer to responses…as it could be coincidental and not related.
Maybe you’re hearing the beat frequency between different parts of the colony humming at slightly different frequencies. Just a thought. I’d like to hear it, have you recorded it, Alan?
There are lots of apps you can put on your phone to identify sound frequency, including most guitar tuners. It might help to have something like that for comparison between hives.