"Ouch! They're defending themselves somehow!"

We all know that bees have stingers to defend themselves, yes? The thing is, against some animals, such as a few hornets, those stingers don't work--their carapaces are too hard. So how do the bees defend themselves against that? Well, some of them swarm the hornets, engulfing them in a ball of bees, raising the temperature inside the sphere of insects to temperatures that are lethal to the hornet. Scientists call this "thermo-balling."

But scientists figured this couldn't work against one enemy of theirs, the Oriental hornet, because it can withstand temperatures of 122 degrees Fahrenheit, whereas the temperature inside the thermo-ball only reaches 111 degrees. But the bees still swarm and manage to kill them. What gives?

Apparently they're smothering them to death.

Alexandros Papachristoforou of Aristotle University of Thessaloniki, Greece, and colleagues made videos of honeybees killing hornets.

They noticed that the bees press on the insects' abdomens, so they set up an experiment to see if perhaps the bees were suffocating the hornets.

Insects breathe through openings in their exoskeletons called spiracles. These are covered by structures known as tergites when air is released.

Using tiny tweezers, the scientists propped the tergites open with teensy pieces of plastic.

"It took much longer for honeybees to kill hornets equipped with plastic blocks than those without," the researchers wrote.

"To kill the high-temperature tolerant hornet, Cyprian honeybees have developed an alternative strategy to thermo-balling. They appear to have identified the hornet's 'Achilles' heel,'" the researchers concluded.