If you are wondering why a "banana" smell to alarm and sting
pheromone, that is the specific smell of 2-Heptanone, one
of the significant components of the pheromone.  It has a 
bit of a metallic edge to it, so it is not exactly the odor 
of a banana.

Regardless, a banana is a very poor choice of fruit for a
bag lunch to be taken on a day of beekeeping, as it might
lull you sense of smell to that odor.

If you can smell the "banana" smell, it is time to back off
and take a break.  Go work the hives at the other end of
the yard, and let that one calm down.

And I must add my voice to the protest over the use of the
term "aggressive".  No such thing as "aggressive" bees.  They
are only defensive, decades of cartoons to the contrary.

Some hives are merely more defensive than others... :)

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