The Science of Decomposition: Why Body Farms Exist and How They Operate

Recently, researchers in New South Wales, Australia, reported that bodies left outdoors in the local climate can move on their own during decomposition. Such studies are currently conducted only on two continents—North America and Australia—where special sites called “body farms” are set up. These facilities often face protests from local residents, but their work is crucial for both practical purposes (training investigators and forensic experts) and theoretical research, allowing for clinically accurate reconstructions of decomposition and the study of the necrobiome. Here’s how body farms came to be, why they are necessary, and the legal and ethical considerations surrounding them.

Everything Depends on the Conditions

There is no single classification for the stages of decomposition—different schools and authors have their own approaches. Generally, the process unfolds as follows:

• After biological death, due to the cessation of blood circulation, early postmortem changes begin. The body cools to match the ambient temperature as metabolism stops.
• Rigor mortis sets in as muscle proteins lock, causing the body to stiffen and joints to fix in a semi-bent position. Blood settles in the lower parts of the body, forming purplish-blue postmortem stains.
• Autolysis begins: cells self-destruct due to enzymes that, during life, were involved in metabolism. This leads to tissue breakdown and fluid release, causing the skin to blister and peel.
• Putrefaction follows, driven by anaerobic bacteria from the body (mainly the gut) and the environment, as well as fungi. These microbes break down complex biological molecules into foul-smelling compounds. Gases produced cause bloating, and fluids leak from natural openings and skin tears. Hemoglobin turns into sulfhemoglobin, giving the body a greenish tint.
• Autolysis decreases over time, while putrefaction increases, creating conditions for insect larvae to colonize the body and speed up tissue breakdown. Scavenging animals may also play a role. Eventually, only bones and teeth remain, which can last for years or even millennia if fossilized.
• In certain conditions, instead of putrefaction, preservation processes can occur, such as mummification (high temperature, low humidity, good ventilation), adipocere formation (high humidity, low oxygen, often underwater), peat bog preservation, freezing, and more. Artificial preservation, like embalming, is also possible.

The timing of these stages varies greatly depending on temperature, humidity, rainfall, oxygen availability, the body’s condition at death (including body mass, diseases, digestive tract contents), burial (depth, soil type, container), clothing, presence of scavengers, and preservation factors.

How It All Began

People have tried to study postmortem changes for forensic purposes since ancient times. The first known systematic work was by Chinese official and scholar Song Ci in the 13th century. His book included instructions for examining and autopsying bodies, as well as observations on the effects of insects and weather on decomposition. In Europe, similar works appeared centuries later, with regular publications only starting in the late 18th century. Modern forensic science began to take shape in the second half of the 20th century.

Despite advances like DNA analysis, most time-of-death estimates still rely on postmortem changes observed in previous cases or animal experiments, often with limited accuracy. In 1977, forensic anthropologist William Bass made a notable error when he misjudged the age of a body found in a Civil War grave, not realizing it had been preserved by embalming and a metal coffin. This mistake inspired him to create an outdoor laboratory to systematically study human decomposition under controlled conditions.

In 1980, the first Anthropology Research Facility (ARF) opened at the University of Tennessee in Knoxville, later becoming the Forensic Anthropology Center (FAC). The term “body farm” was popularized by author Patricia Cornwell, and Bass himself titled his autobiography “Death’s Acre.” Today, there are eight such facilities in the U.S., known as body farms, dedicated to advancing knowledge of human decomposition to aid forensic investigations.

Life After Death: How Body Farms Work

The oldest body farm is a fenced-off forest area (now over 2.5 acres) where fresh bodies are placed in various conditions—outdoors, in shade, in cars, in water, buried at different depths, clothed or unclothed—to study decomposition. Staff and student volunteers document every stage using cameras, visual observation, and sample collection. The facility also includes a morgue, laboratory, and other support buildings.

Once a body is fully skeletonized, the bones are cleaned and added to a collection used for research and forensic anthropology training. Experts learn to determine sex, age at death, ancestry, body type, and certain diseases from well-preserved skeletons. Demographic, medical, and anatomical data about donors are stored in a special database.

The collection now contains over 1,800 skeletons of people of all ages and backgrounds. Each year, more than 100 bodies are donated, about half through pre-arranged bequests and the rest by relatives of the deceased. Unclaimed bodies make up a small percentage.

The success of the original facility led to the creation of six more in the U.S.—in North Carolina, two in Texas, Illinois, Colorado, and Florida—each studying decomposition in different climates and serving as training centers for forensic professionals, including the FBI. In 2016, Australia opened its first and only body farm near Sydney.

Body farms have amassed extensive data on the chemical and biological processes of decomposition and how various factors affect them. High-tech research includes sequencing microbial genomes, proteomics, isotope analysis, and more. This has led to a detailed understanding of which bacteria are responsible for decomposition under specific conditions, confirming that a corpse is a dynamic ecosystem where microbial populations change with each stage of decay. These ecosystems, first studied in animals, are called necrobiomes (“the living community of death”).

Necrobiome research has already yielded important findings: for example, aerobic bacteria give way to anaerobic ones during bloating, oral microbes can serve as “clocks” for estimating time of death, and animal models are not always accurate for human decomposition. Analysis of decomposition gases has led to the development of devices like LABRADOR for detecting buried crime victims, a technology expected to become widespread in the coming decades. Australian researchers also found that bodies can move much more during decomposition than previously thought, which is important for crime scene investigations.

Controversy and Public Reaction

Despite their scientific value, body farms often face opposition from neighbors and activists. After a 1995 TV investigation in Knoxville, some residents complained about odors or even seeing decomposing bodies, prompting the facility to build a higher fence. The group “Solutions to Issues of Concern to Knoxvillians” (SICK) staged protests, but with little effect. Lawsuits are occasionally filed, mainly against new facilities, but the number of body farms continues to grow.

One notable case involved the opening of the largest body farm at Freeman Ranch in Texas, where locals and a nearby airport worried that vultures would be attracted. The University of Texas, which runs the farm, proved there was no danger and even included vulture studies in its research program, later publishing the results.

While the topic is sensational, most media coverage—both tabloid and serious—portrays body farms positively, highlighting their benefits for science and society. Artists and writers, from Patricia Cornwell to photographer Sally Mann, have also explored the subject. William Bass and journalist Jon Jefferson have even co-authored a series of detective novels popularizing forensic anthropology.

Legal and Ethical Considerations

In the U.S., there are no special laws for body farms; they operate under general regulations for body donation to science. Bodies can be used for research and education if they are unclaimed, donated by the deceased through a will, or given by next of kin. Forensic archaeology centers follow similar principles, often with fewer restrictions than medical schools. The main requirements are that the donor’s body weight does not exceed 500 pounds and that they do not have HIV, viral hepatitis, or antibiotic-resistant infections.

The law on body donation is interpreted broadly: since the 1930s, the auto industry has used bodies for crash tests, and the defense industry for studying the effects of weapons. Such uses sometimes shock families who thought they were helping disease research, not realizing their loved ones’ bodies might be used in less “noble” experiments. Scandals involving unethical companies that treat bodies as commodities have led to lawsuits and eroded trust in body donation, which is always in short supply.

While organ donation is generally seen as noble, donating one’s body to science still carries a stigma. Yet, while organ donation can save individual lives, body donation to science can help save many more, albeit less directly.