Suicide is painless

My bees are suicidal. Seriously, they have a death-wish and I'm beginning to suspect that chronic depression among the world's honey bee population is the reason for their decline. I rest my thesis on the following observation:

The bees I received from my bee-buddy were queenless and without a laying queen the colony was going to die out over the next couple of months. Fortunately I had raised a new queen and she was laying well in her little box, so it was time to introduce her to the queenless colony. You would think they would welcome her as their savior, but queen introduction is risky. So I placed her in a little cage to protect her from the workers and plugged up the exit hole with a wodge of icing sugar fondant. The idea is that the workers eat their way through the icing sugar and by the time they reach the queen they have got used to her smell and moreover are feeling too full of sugar to have the energy to harm her. Instead they start feeding her and within a day she is out and about in the colony and shortly thereafter she should be laying.

Except she wasn't. I opened up the hive a week later and there were hardly any eggs to be seen. So I hunted around to try and find her without success, until I noticed a bunch of bees in a huddle...

Huddles mean trouble. I poked my finger in the huddle to try and separate the bees and sure enough, there in the middle was the queen. They were killing her by 'balling' her, a process that involves smothering their victim and vibrating their bodies to generate so much heat that she would die of hyperthermia.

There was nothing I could do - she was finished, and so is the entire colony.