Worker bees will cuddle an old queen bee to death!

When a queen bee is getting old or sick, the worker bees start rearing replacement queens. Once a new queen is available, the workers need to get rid of the old one.

Workers will cluster tightly around the queen until she dies from overheating. This is colloquially known as cuddle death.

Interestingly, Japanese honey bees use this to kill predators and also against foreign queens attempting to take over an existing colony.

(Source)