So I have a tree. It has 2 beehives on opposite sides. The leaves extend 2 blocks from the trunk. The bee was a direction from the tree not with a beehive (beehive on east & west, bee was south). It started raining so the bee tried to go to a beehive, but once it got under the leaf cover, it turned back into the rain, then it turned around to go home. It did this for a while before it got dark so all it wanted to do was go home.

I imagine what it's doing is trying to go home once it starts raining, but once it wasn't in the rain it thought to go to the flowers. But then getting out into the rain it thought to go home. Until finally it was dark so the only thing on its mind was to go home.
TL:DR the AI to go home in rain isn't active for long enough for it to go into a beehive before returning to work.