Cyprian honey bees under attack by predator hornets have evolved a grisly and lethal way of fighting back which scientists have called "asphyxia-balling," according to a study published Monday.

An intruding hornet looking for a snack in a beehive may suddenly find itself enveloped inside a buzzing ball of black-and-yellow worker drones. The bees squeeze in tightly around the abdomen -- where hornets breath -- until the would be aggressor dies of suffocation.

Bees suffocating hornet

A team of Greek and French biologists, led by Alexandrous Papachristoforou of Aristotle University, observed this insect drama dozens of times, both in the laboratory and in nature.

The average time for smothering a hornet was 57.8 minutes.

The technique used by Apis mellifera to dispatch its most formidable enemy, reported in the British journal Current Biology, differs in crucial ways from that used by its Asian cousin.

Asian honey bees also form a deadly scrum around a hornet but rather than smothering the attacker, they kill it by raising the hornet's body temperature -- by pressing in while buzzing their wings -- beyond a critical threshold.

Cyprian bees, however, cannot generate enough heat to kill by "thermo-balling" and thus crush in on the hornet's abdomen.

In the end, the researchers conclude, the hornet dies from a combination of overheating, carbon dioxide poisoning and lack of oxygen.