I saw this older article in the sidebar while reading that other recent ant article. I thought it was also neat and worth a separate post.
When hives of the African lowland honeybee (Apis mellifera scutella) collapse, they do so because of an invisible inner threat: the growing, immortal clone army of a rival bee subspecies.
That army is possible because the female workers of the rival subspecies — the South African Cape honeybee (Apis mellifera capensis) — can create perfect copies of themselves, with one individual found to have done so millions of times in the past three decades.
With this perpetual-cloning ability, the Cape honeybees sneak into the hives of their lowland honeybee rivals and churn out copy after copy with no need for a queen. Even worse, these clones are freeloaders, refusing to do any work.