Beasts, Bees, and Bad Air

Poisoned arrows, snake-filled jars, toxic smoke, and contaminated provisions appear in accounts of warfare long before the gas attacks of the First World War. Some episodes have archaeological evidence behind them; others survive in stories written long after the event. They describe attempts to exploit an enemy's dependence on food, water, breathable air, and the ability to work or fight in confined spaces.

“Biological and chemical warfare” is a modern category, and it fits these examples unevenly. Poisoning an arrow, releasing bees, burning a siege engine, and attempting to spread disease involve different methods and intentions. Commanders used them to disable troops, interrupt assaults, or deny access to a position. Their effectiveness depended on local knowledge, delivery, and conditions that a commander could influence only so far. Greek mythology gave that danger a memorable form in the story of Heracles and the Hydra.

Heracles and the Hydra

Heracles, the son of the god Zeus and a mortal woman, was known to the Romans as Hercules. His Twelve Labors were tasks imposed on him by King Eurystheus, each demanding an extraordinary feat of strength or endurance. The second took him to the marshes of Lerna in southern Greece. There the Hydra, a great serpent with many heads, emerged from its lair to ravage the surrounding country and its cattle.

Heracles forced the creature into the open and attacked it with his club. The Hydra coiled around his leg, holding him close while he struck at its heads. Each head he destroyed was replaced by two. So he called on his nephew Iolaus for help.

Iolaus brought burning brands. As Heracles removed each head, his companion seared the stump before new ones could grow. Working together, they overcame the creature until only its immortal head remained. Heracles cut that off too, buried it beside the road, and placed a heavy rock over it. He then opened the Hydra's body and dipped his arrows in its venom. He carried the poisoned arrows away for use against other enemies.

Years later, Heracles and his wife Deianeira reached a river where the centaur Nessus earned his living carrying travelers across. Heracles crossed under his own strength and entrusted Deianeira to the ferryman. During the crossing, Nessus tried to rape her. Hearing her cries, Heracles shot Nessus through the body with one of the arrows poisoned at Lerna.

As he lay dying, Nessus called Deianeira to him. Blood gathered from his wound, he told her, would serve as a love charm. If Heracles ever fell in love with another woman, the charm would restore his love for Deianeira. She accepted the promise and preserved the substance. Nessus' blood contained the Hydra's venom from the arrow that had struck him. His death left her in possession of the means to kill his killer.

The supposed charm remained unused for years. Then Heracles attacked and sacked the city of Oechalia, taking a young woman named Iole captive. Deianeira learned of her and feared that her husband would fall into love with his captive. Coincidentally, at the same time, a messenger arrived asking for fine clothing: Heracles was preparing a sacrifice and needed a suitable garment. The request gave Deianeira an opportunity to use what Nessus' supposed love charm.

She treated a robe with Nessus' blood and gave it to the messenger, hoping to renew her husband's love for her. Heracles was to wear her gift at the sacrifice.

After the messenger had left, Deianeira noticed what had happened to a piece of wool she had used to apply the blood. Left in sunlight, it had shriveled and crumbled away. She began to understand what the dying centaur had given her. Nessus had used her fear for her marriage to arrange his revenge, and she had entrusted his poison to the messenger herself.

Heracles put on the robe and began the sacrifice. As the garment warmed, the Hydra's venom began to burn his flesh. The cloth clung to his body. When he tried to tear it away, his flesh came with it; removing the robe brought further injury without ending the pain. Their son Hyllus witnessed his agony and returned home to tell Deianeira what had happened.

Hyllus blamed his mother for his father's suffering. Deianeira withdrew into the house without answering him. Later, when Hyllus and a nurse entered the marriage chamber, they found her dead. She had taken her own life before Heracles learned that she had intended to win back his love.

Heracles eventually had himself taken to Mount Oeta, where he ordered a funeral pyre built and lay down upon it. His companions at first refused to light it. When the fire was finally kindled, it ended his mortal suffering; in the myth, he was then taken up among the gods. The victory at Lerna had supplied the venom that killed Nessus, enabled his revenge, and brought both Heracles and Deianeira to their deaths.¹

The story links the attraction of poison to the difficulty of controlling its consequences. Heracles made his arrows more deadly, then lost control of the venom once it entered another creature's blood. In the historical accounts that follow, the same concern takes practical and moral forms: how to use a dangerous substance effectively, how to protect others from it, and whether the advantage justifies the means.

War Outside the Rules

Ancient judgments about acceptable weapons varied between societies and within them. Authors who praised courage in open battle could also admire ambushes, deception, and siegecraft. Poison attracted particular objections because it concealed the means of injury and could endanger people beyond the intended target. Those objections coexisted with accounts that celebrated a successful stratagem. The circumstances of a war, the author's sympathies, and the identity of the victim all influenced how an incident was told.

Poisoned Arrows

Greek and Roman writers associated the Scythians with poisoned arrows. Their descriptions included mixtures of snake venom and putrefying substances. Such accounts came through literary traditions that often emphasized the supposed cruelty or strangeness of peoples beyond the Greek and Roman world. They support the existence of a reputation for poison weapons more securely than they establish a standard recipe or its frequency of use.

Knowledge of hunting poisons offered one route into military use. Plant toxins and animal venoms could be applied to an existing projectile without changing the bow or the way an archer fought. Preparing and handling the points introduced hazards of their own. The practical questions concerned the substance used, how well it kept, and whether enough entered the wound to have an effect.²

Poison added uncertainty to an injury that was already difficult to assess. An ordinary arrow wound could become infected or prove fatal after the fighting; a poisoned point introduced another possible cause of deterioration. Ancient descriptions of pain, swelling, fever, or collapse rarely allow a precise diagnosis. The fear was easier to convey than the cause: a man who survived the strike could still become seriously ill.

The belief that an enemy used poison could make even a slight wound alarming. The uncertainty extended to the men tending the injured: removing an arrow offered no assurance that the danger had passed.

Mad Honey

During the retreat of 401–400 BC, Xenophon's Greek mercenaries encountered toxic honey near Trapezus on the Black Sea. Men who ate it vomited, suffered diarrhea, and became unable to stand. Those who consumed the most appeared gravely ill. They began recovering the following day and were able to resume the march after several days. The episode describes an accidental poisoning that temporarily disabled soldiers already traveling through difficult country.³

The modern explanation is grayanotoxin poisoning from honey produced with the nectar of certain rhododendrons. Its effects include weakness, vomiting, low blood pressure, and disturbances of heart rhythm. The severity varies with the honey and the quantity eaten. This helps explain how a food gathered locally could incapacitate men who then recovered over the following days.⁴

More than three centuries later, an account of fighting during Rome's wars with Mithridates VI describes a deliberate use of the same hazard. Local people left toxic honeycombs in the path of Roman troops, then attacked after the men had eaten them and become incapacitated. The report attributes to local knowledge an advantage the invaders lacked: the ability to recognize a dangerous food and anticipate its effects.⁵

Xenophon's men encountered the hazard by accident. In the later account, local opponents arranged the encounter and attacked while the Romans were incapacitated. The military opportunity lay in that interval. Men unable to stand could neither fight nor guard their supplies; recovery several days later offered little protection against an attack during the illness.

Snakes, Bees, and Scorpions

Hannibal's reported use of snake jars belongs to the later part of his career, when he served Prusias of Bithynia against Eumenes of Pergamon. According to the account, he had venomous snakes collected in earthenware vessels and ordered the jars thrown onto enemy ships. The Pergamene crews initially treated the pottery with amusement, then broke off the fight when the jars shattered and released their contents. The story presents confusion aboard crowded vessels as the means of overcoming a stronger fleet.⁶

The confined working space of a warship helps explain the tactic. Sailors and fighting men needed room to move and had tasks that depended on coordination. Avoiding loose snakes would compete with those tasks, even if few men were bitten. The account gives us a successful ruse without enough detail to measure the animals' contribution separately from the rest of the naval action.

Bees, hornets, and wasps offered similar possibilities around fortifications. Men climbing ladders, moving a ram, or working beneath a wall were occupied with tasks that left little room to deal with a swarm. A nest or hive delivered among them could interrupt an assault. Getting the insects to the right place while protecting their handlers was a separate difficulty. Once released, they could sting anyone within reach.

Hatra provides a less certain example. Herodian describes the defenders of the Mesopotamian city throwing vessels containing poisonous winged insects at Roman attackers. The familiar identification of these creatures as scorpions is an interpretation, and it sits awkwardly with the description of flight. The passage preserves a report of animal weapons in a siege; it leaves the creatures' identity unresolved.⁷

Collecting animals, keeping them alive, and delivering them imposed costs that the successful anecdotes tend to pass over. A broken jar or a disturbed hive could expose the handlers before the weapon ever reached an enemy.

Poisoned Water

A besieged city depended on wells, cisterns, conduits, or access to springs. An army on the march needed reliable water at its camps. Contaminating a supply offered a way to weaken resistance without first defeating the troops guarding it. The same dependence made rumors of poisoning difficult to ignore.

The Greek tradition of the siege of Kirrha describes attackers putting hellebore into the city's water. The plant was known for its purgative effects, and the story explains the defenders' defeat through illness. It survives in later accounts with differing details. The event and the means of carrying it out remain uncertain.⁸

Poisoning a shared supply exposed a wider population than a poisoned projectile did. Soldiers, civilians, and animals might all drink from it. The attacker also needed access to the water and enough of the substance to have an effect under the conditions of that supply. These practical questions are often harder to answer than the account's claim that the defenders became ill.

Crowding, inadequate waste disposal, and unreliable water also made besieged populations vulnerable to illness without any deliberate contamination. These conditions complicate the stories of poisoning: disease inside a city could have several causes, and the defenders were poorly placed to determine which was responsible.

Bad Air: Smoke and Siege Mines

Smoke could make a confined position impossible to occupy. At Ambracia, defenders detected Roman digging by sound and opened a countermine. After fighting underground, they used a device burning feathers to drive smoke toward the Romans and force them out. The conditions that protected miners from missiles above ground also restricted their escape from smoke below it.⁹

Mining was a contest between engineers and laborers as well as soldiers. Attackers dug beneath defenses to undermine a wall or tower; defenders tried to detect them and intercept the work with a countermine. If the tunnels met, the defenders had an opportunity to stop the attack underground. A fire near that junction could deny access without a prolonged struggle in the passage.

The military use of smoke overlapped with older explanations of illness through corrupted air, but the two should be kept distinct. A choking fire in a tunnel had a direct effect on the men breathing its fumes. A foul smell or a report of unhealthy air, by itself, tells us much less about the cause of disease. Ancient explanations could guide useful precautions without accurately identifying how an illness spread.

Smoke also depended on the setting. It dispersed in open ground and concentrated in enclosed passages. Airflow influenced where it went, and a fire could endanger the men who lit it. At Dura-Europos, the source and movement of smoke are central questions in interpreting the deaths of soldiers in a countermine.

The Mines at Dura-Europos

In the mid-third century AD, the Roman-held city of Dura-Europos on the Euphrates came under Sasanian attack. Along its western defenses, the Romans strengthened the wall with an internal rampart while the attackers used ramps and mines. Near Tower 19, the Romans dug a countermine to intercept a Sasanian tunnel. Twentieth-century excavations found the remains of roughly twenty Roman soldiers crowded together in the underground works, with another body interpreted as a Sasanian nearby.

The original explanation involved close combat and fire. Simon James's later reanalysis proposed that the Sasanians deliberately used toxic smoke against the Romans. His argument drew on the position of the bodies, the tunnel arrangement, and finds of bitumen and sulfur. In this reconstruction, a fire produced fumes that incapacitated the Roman party. The attackers then moved or piled bodies to obstruct the countermine before continuing their work.¹⁰

The tunnels, combustible materials, and human remains allow that reconstruction to be tested against a physical setting. Deliberate gassing remains an interpretation of the finds. The exact sequence of deaths and the movement of the bodies are uncertain.

Fire and Incendiaries

Fire was a familiar siege weapon. Armies burned gates, engines, defensive works, and ships, using materials such as pitch, resin, sulfur, and oil. Incendiaries belong at the edge of this discussion because their usefulness often rested on keeping a fire burning where an enemy could neither tolerate it nor readily put it out.

A wooden ship offered abundant fuel in its hull, rigging, and stores. Its crew had limited room to fight a fire and few safe places to withdraw. Against a wall or siege tower, an incendiary had to reach exposed combustible material and remain there long enough to take effect. A substance that adhered to a surface or spread across it offered advantages over a brief flame.

Petroleum-based incendiaries were part of this tradition. Byzantine Greek fire became its best-known later development, especially in naval warfare. Its precise composition remains debated, and the name has accumulated claims that are difficult to separate from its reputation. Accounts describe a projected incendiary that burned fiercely and was difficult to extinguish. The delivery apparatus and the skill of its crews were essential to its military use.¹¹

An incendiary mixture had to be stored and handled near the people expected to use it. Wind, movement, and damage to its container or apparatus could turn it against them. Specialized equipment increased the need for trained crews and careful preparation. Knowing that a substance burned was only the beginning of making a useful weapon from it.

The comparison with animal weapons is practical. Both required a means of keeping a dangerous payload contained until delivery. Fire could spread after it reached the target, while animals could move beyond it. Releasing the weapon reduced the user's control over who or what it reached next.

Plague at Caffa

In 1346, forces of the Golden Horde under Janibeg besieged the Genoese trading city of Caffa, now Feodosia in Crimea. Plague struck the besieging army. Gabriele de' Mussi reported that the attackers hurled infected corpses into the city with siege engines. He was not an eyewitness to the siege, and the reported act lacks independent confirmation.¹²

The episode is often linked to the arrival of the Black Death in Europe. That connection requires several separate judgments: whether the bombardment happened, whether it transmitted plague within Caffa, and how infection traveled from the Black Sea to other ports. Siege engines could throw bodies. That establishes the method's feasibility without establishing that it occurred or explaining its effect on infection.

Trade and shipping connected Caffa to a much wider area already exposed to plague. Disease could travel with people, animals, and their parasites through several routes. One reported act at Caffa cannot explain the European pandemic. Mark Wheelis argued for the plausibility of de' Mussi's report while distinguishing transmission at Caffa from the broader spread of plague.¹³

For the defenders, a bombardment with corpses would have posed an immediate problem of removal and disposal, whatever its effect on infection. It would also have been intelligible within ideas that connected disease with decay and corrupted air. An attacker did not need to understand plague transmission to intend harm through infected remains.

The Hydra's Lesson

The examples differ in their evidence and their military purpose. A poisoned arrow targeted an individual; toxic honey could disable a group; smoke could deny a tunnel; an incendiary could destroy a ship. Their usefulness depended on circumstances that the memorable stories often compress or omit. Collection, storage, delivery, weather, and the enemy's behavior all influenced the result. Reports of success tell us little about how often comparable efforts failed.

The Hydra had long been defeated when Deianeira sent the robe to Heracles. Its venom survived in his arrows, entered Nessus' blood, and returned through a gift she believed would restore their marriage. In warfare, the route from advantage to injury could be much shorter. A change in wind or a broken container could expose the men preparing a weapon before it ever reached the enemy.

Pre-modern armies could recognize and exploit natural hazards through observation and local experience. Making those hazards serve a specific military purpose was harder. The enduring problem was containment: keeping the poison, animal, fire, or disease dangerous to the enemy while protecting everyone expected to handle it and live near it.

Notes

Bibliography

Apollodorus. The Library. Translated by James George Frazer. 2 vols. Heinemann, 1921. Reproduced in Theoi Classical Texts. https://www.theoi.com/Text/Apollodorus2.html.

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James, Simon. “Stratagems, Combat, and ‘Chemical Warfare’ in the Siege Mines of Dura-Europos.” American Journal of Archaeology 115, no. 1 (2011): 69–101. https://doi.org/10.3764/aja.115.1.0069.

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Sophocles. Women of Trachis (The Trachiniae). Translated by R. C. Jebb. Internet Classics Archive, n.d. https://classics.mit.edu/Sophocles/trachinae.html.

Wheelis, Mark. “Biological Warfare at the 1346 Siege of Caffa.” Emerging Infectious Diseases 8, no. 9 (2002): 971–75. https://doi.org/10.3201/eid0809.010536.