Worker bees detect and kill upstart queens.
Not sure what this has to do with selfishness. Is the worker bee killing an upstart-queen from its own hive? If so, what's its motivation to kill the upstart-queen? How does this benefit the worker bee, causing the behavior to be selfish?
Human cells are being destroyed all the time (apoptosis)
In the case of body cells and apoptosis, I'd view the actual human being as equivalent to the entirety of the hive/the queen bee, in which case, the process of apoptosis is selfless from the point of view of the cells killing themselves or other cells - in theory it's for the good of the human being as a whole.