Have you ever wanted to provide valuable assistance into a criminal investigation but don’t have the time, resources, or technical ability? Not to worry. You can still help by donating your corpse to a body farm.

Less than a dozen body farms, including prominent locations in Tennessee and Texas, are scattered around the world. These forensic facilities provide valuable insight into body decomposition by carefully monitoring the dead as they deteriorate under a variety of environments—from cold winters that can slow the withering process to searing climates that can speed it up. Such studies fall under the purview of forensic taphonomy, or the study of what the body experiences between death and discovery. It may sound morbid, but the science can help law enforcement better pinpoint the time and method of death in cases involving foul play. For more on these scientific graveyards, keep reading.

1. The first body farm opened as a result of a Civil War mystery—and maggots.

Forensic anthropologist William Bass was working for the University of Tennessee and the state's medical examiner's office in the 1970s when he was struck by a strange new variable in his analysis of corpses: maggots.

Having spent much of his career in Kansas, where bodies can go years before being discovered due to the wide swaths of unoccupied land (by which time the maggots were usually long gone), Bass realized he knew little about how the insects could help pinpoint time of death for "fresh" corpses. There wasn't much in forensic literature about them, either. His concerns over the imperfect understanding of decomposition were heightened when local police asked for his assistance with a strange case: They'd recently discovered that the grave of a Civil War-era colonel named William Shy had been disturbed. Inside the casket was a body that looked oddly well-preserved for having spent over 100 years in the ground. Police suspected someone had swapped Shy’s body for that of a recent crime victim. That turned out not to be the case—Shy was simply well-embalmed in a tightly sealed casket—but it was further evidence the science of post-mortem investigation needed to be brought up to date.

Up until then, forensic analysis had been limited to pig carcasses. Bass decided to make the study of decomposing human corpses his primary focus, and set up a 1.3-acre plot on a farm donated to the university outside of Knoxville. By the end of the 1970s, the first body farm was open and running.

2. People donate their corpses to body farms for different reasons.

The body farm at the University of Tennessee has seen roughly 1800 corpses pass through its grounds, with another 4000 pledging to join them in the future. Why would anyone agree to such post-mortem treatment? For some, the donation of their bodies to science is reason enough. Body farms typically have fewer requirements than medical schools, which often put limits on the deceased’s body weight or reject bodies that have undergone an autopsy. (It’s also worth noting medical schools can only dissect a body once, while bodies at the farms can provide information for months.) Others may want to apply their philosophy about returning to the earth and allowing their body’s nutrients to be “recycled.” For others, cost is a consideration. Funerals can run into the thousands of dollars. At the Texas State body farm, dubbed Freeman Ranch, pick-up is free.

3. Bodies experience a variety of fates at the farms—including vultures.

At Freeman Ranch, bodies are observed while under siege by a variety of different elements. The field is typically made up of about 50 corpses at a time: Some go directly under the sun, while others rest in the shade. A few might be positioned in cars or in sheds. Scientists put many bodies in a cage to prevent animals from interrupting the process, while other bodies are left out and vulnerable to animals—including vultures—to determine what kind of damage can be inflicted. A rat, for example, will only gnaw on fresh, greasy bone, whereas a squirrel will chomp on an older, dry bone. That helps investigators know that if they see squirrel bites, the body is probably at least a year old.

Of course, corpses will see deterioration with or without the involvement of predators. Once the body’s cells rupture during the decay process, skin begins sloughing off. Bacterial growth within the body leads to the release of gases that can bloat a corpse to twice its normal size. That leads to flies, who lay eggs and introduce maggots that feed on flesh. Leaking fluids, bacteria, and maggots all conspire to eventually render the body a bony remnant, left to dry out and mummify. Within six to 12 months, nothing will remain but bone, some skin, and cartilage. Temperature and exposure can alter the timing of these processes, however: In cooler climates, for example, flies may not be in any hurry to lay eggs, as they prefer to do that in warmer months.

4. The term body farm has mysterious origins.

William Bass and his anthropological cohorts didn’t coin the catchy phrase body farm. The official name for their research area is the Forensic Anthropology Center. The term body farm is sometimes credited to Knoxville police, who began using it as slang in the 1980s. Others cite novelist Patricia Cornwell, who wrote a 1994 crime novel titled Body Farm and included a character conducting research similar to Bass. The character, Lyall Shade, appears in several Cornwell novels tending to the fictional Knoxville Body Farm.

5. Body farms let law enforcement conduct mock exhumations.

Not all bodies at body farms remain exposed to the elements. Some locations, like the University of Tennessee’s, invite law enforcement officials to come and dig up bodies so they can better understand the anatomy of bones, how bodies are positioned in graves, and how to collect forensic evidence. The Federal Bureau of Investigation (FBI) has been sending agents to the Tennessee site for the past 20 years.

6. Body farms find even skeletal remains useful, too.

Once a body has finished decomposing and has reached the point where observation is no longer useful, the remaining bones are often stored so they can be used for comparison purposes later on. Why? Human skeletal structures can vary depending on lifestyle habits. People carrying excessive weight might have more joint wear, for example. In 2008, anthropology professor and Texas State body farm director Daniel Wescott noticed that the remains of a decapitated body had slender thigh bones. Based on samples from the University of Tennessee, Westcott surmised that the bones were smaller than usual because the victim spent time in a wheelchair. The tip allowed the public to assist authorities in identifying the victim.

7. Body farms maintain photo rights.

If you’re squeamish about extensive photographic analysis of your body or your dearly departed's, it’s best not to donate to a body farm. Most farms retain photographic rights, which means you could end up in a National Geographic documentary or embedded in an article that uses your now-deceased self to illustrate the finer points of decay for the public at large.

8. The bones at body farms sometimes go back to loved ones.

Body farms are typically fenced-in and covered by security cameras to avoid trespassers or any other unintended indignities being visited upon their occupants. The University of Tennessee site is not open for public tours. But after decomposition ends and bones are stored? That’s another story. The university allows scholars and investigators to check out the bones like books for examination and then return them. The offer is also open to relatives of the deceased. On average, four to six families a year request to see the skeleton of their loved one and get more information on how their death is helping science.