The belief that the dead can rise from their graves is an ancient one, and so too is the desire to make sure the dead stay buried. People throughout history have used rocks, iron rods, sickles, padlocks and other methods to prevent corpses from reanimating. These practices seem to be rooted in the idea that if a corpse got up again, it might harm the living.

Scholars have posed many theories about why historical people feared the walking dead. Some may have worried that those who died under unusual or taboo circumstances were more likely to come back again. Others may have believed that people who died of particular diseases could continue spreading them after death.

Whatever the reason, here are some of the ways that people have tried to keep corpses in their graves.

1. Bury Under Rocks

Ancient Greeks worried that a body, once buried, could rise from the dead as a revenant and harm the living. Archaeological findings suggest that ancient Greeks tried to prevent this by burying corpses under heavy objects.

In an ancient Greek colony on Sicily, two graves show possible anti-revenant practices. One contains an adult corpse whose head and feet were covered with heavy ceramic fragments. The other contains a child whose body was covered with five large stones. Archaeologists discovered these graves in a necropolis that dates from the 5th to the 3rd centuries B.C.

2. Iron Rod Through Chest

Medieval Europeans feared the walking dead, too. Superstitions about vampire-like creatures varied by region, and there were multiple beliefs about how to make sure a corpse didn’t rise from the dead to sicken or kill the living.

In the ancient city of Perperikon in Bulgaria, archaeologists discovered the remains of a 13th-century man with an iron rod from a plowshare through his chest. His left leg was separate from his body and laying beside him. In addition, researchers identified two 14th-century skeletons in Sozopol, Bulgaria buried with a plowshare rod or other piece of metal piercing their bodies.

3. Brick in Mouth

Stories of vampires and other undead creatures may have helped communities explain outbreaks of disease. Scholars theorize that performing an anti-vampire ritual on the body of someone who died of a particular disease could be a way of trying to prevent that person from rising and spreading their sickness.

Archaeologists have suggested that this is why a 16th-century woman found in a plague grave in Venice, Italy was buried with a brick in her mouth. The brick may have been intended as a way to prevent her from harming others and spreading the plague after death.

4. Soil in Mouth

Different regions in Europe had different conceptions of what vampires were and how they used their powers. In Germany, the Nachzehrer was a vampire-like creature that stayed in its grave and harmed the living supernaturally by chewing on its burial shroud.

The belief that corpses chewed on their burial shroud may stem from the fact that a corpse’s purge fluid could cause the burial shroud to tear at the mouth, making it seem as though the corpse had been chewing on it. A 1679 tract called “On the Chewing Dead” said that a person could prevent a Nachzehrer from harming the living by stuffing its mouth with soil to prevent it from chewing. The tract suggested a rock or a coin in the mouth could also work.

5. Sickle Across Neck

Another historical method of preventing the dead from rising was burying a corpse with a sickle across its neck. This may have been a way of ensuring that if a corpse tried to get up, it would decapitate itself.

In Drawsko, Poland, archaeologists discovered four people buried with sickles across their throats in a cemetery used during the 16th and 17th centuries. In addition, the archaeologists identified one woman with a sickle across her pelvis, as well as a rock on her neck and a coin in her throat.

Archaeologists discovered another woman buried with a sickle across her throat in a 17th-century cemetery in Pień, Poland. But in addition to the sickle, there was also a padlock tied to her big toe.

Near her grave, archaeologists identified another corpse with a padlock on its foot. This corpse was that of a young child who was not only weighted down with a padlock but buried facing downward. These padlocks suggest that whoever buried these corpses was afraid they might get up again, and wanted to pin them in their graves.

7. Burning the Organs

In the 19th century, tuberculosis spread through New England, causing people to cough up blood and suffer painful deaths. In an attempt to stop the spread of tuberculosis, then known as consumption, some New Englanders began digging up the bodies of people who had died of the disease and burning their organs.

New Englanders did this because they thought that the people who died of tuberculosis may have been somehow spreading the disease to others after death. This 19th-century vampire panic is one of the clearest examples linking the historical fear of vampires and other undead creatures to disease.