Inspection from Below

I crawled under the California Hive this afternoon to find more clues about the odd knocking noise. The sound seemed to correlate with bees pinging against the screened bottom board.

There is an empty box (except empty top bars) at the bottom of this hive. The bees have not started drawing comb down below.  On the screened bottom board, there were a lot of bees inside, and two outside.  The bees seemed to be flying into and bouncing off the bottom of the screened board. That is what made the sound.

It is odd behavior for bees.

I posted a message on the Honey Bee forum of Permies.  One person thinks it might be a mouse in the quilt. Another thinks it sounds like an insect, not a bee, flying into something like tin.  I will check again later to see if the sound is still happening.

I may have to open this hive up anyway to try some different top bars. I like the bars sold at BeeThinking.