We love bees so much that just about all the comments in this forum contain an implicit, unwriten, belief that cells are just so smart that anything they do in the hive is correct, and whatever they seemingly do wrong is a consequence of our stupid manipulations and interference.

Well, I have evidence that bees can be stupid too (or at least they seem to be):

1) A lot has been said about the importance of ventilation in a hive, the most important from the bees' wellbeeing standpoint perhaps being the reduction of moisture (for us it may be honey production, etc).
In my hives, the only ventilation they get from the hive design is a 1/16 gap between the top super and the inner cover (by glueing stamp-size wood pieces to the corners of the inner cover). This is supposed to help a lot in eliminating moisture and it does quite effectively as judged from the lack of condesation ont the inside surface of the telescopic cover.
Here is the bee's reaction: they propolize this gap shut right away. I have frequently remove the propolis seal when i open the hives only to find it seal the following time I open it. It does not seem related to the size of the gap as I have changed it to less that 1/16 (I have not tried to increase it).

2) Bees sometimes work one side of a frame to make these increadibly deep cells that cross all the way into the other frame's depth (how common is this, I don't know, but in my 3 hives undergoing regression it seems very common). Yesterday I found the following arrangement in one of the frames: One side was drawn to a perfect depth, filled with honey and sealed. ON TOP OF THAT they built a new layer of cells while on the adyacent frame, there was no comb built. HOw smart is that when time comes to reach that honey???

I still think they are pretty smart, with some exceptions.

What others have you seen?