A funny thing happened to me in my hive today...

[Spear]

Did a long over due inspection on one of my hives that I suspected to be queenless, seems my 'fears' are not totally founded, they seem to have a queen as I saw some brood in early development and some eggs near by. However that is not what was funny about this hive inspection. I had hung 3 frames on the frame hanger and had a 4th resting on the ground behind the hive when I noticed a change in the sound of the hive and thought 'Oh Bugger they getting angry off now!' but I was evidently wrong because they showed no aggression at all! The change in tone of the hive was because they all suddenly started fanning at the same time! Even the bees on the frames hanging outside of the hive! I couldn't complain since they were not attacking me and were providing a nice cooling breeze for me to work in -  :lol:
The Hive next to it that I inspected next was also very calm but they didn't fan, but then again I didn't go into the brood nest as I am happy with this hives condition and just wanted to pull some honey from it.

[sarahplusbees]

I've noticed a similar trend in a few of my hives lately, usually after I remove the top body or super, they all start fanning. I find it odd because I generally think of fanning as a way to cool the hive, but with the hive open, I'd have to imagine the breeze would take care of that. Does anyone know what other reasons they might be fanning under these circumstances? Perhaps to distribute pheromones?

[jayj200]

fanning creates heat maybe

[RayMarler]

It could be that the queen was on one of the frames removed from the hive during your inspection. The bees will fan with their little tails up in the air spreading the pheromone scent of the hive out to help guide the queen back, or maybe they are searching for the queen scent by getting the air flows going, trying to find her scent.

It could be the box pulled off had the queen in it, so the bees left in the bottom box started fanning as a way of finding the queen or guiding her back into the hive.