It’s Spooky Season! What do creepy-crawlies have to do with archaeology?

If you know me, you probably know that I love insects–bees, spiders, beetles, I love them all (except ants). It turns out that, whether or not they cause the heebie-jeebies, humans and bugs go way back. For thousands of years, tiny multi-legged critters have been living on us, inside of us, and with us in our homes. Sometimes they were harmless, but sometimes they caused serious problems, like destroying food and spreading disease. And since insects live in such close proximity to us humans, we have pretty much carried them with us wherever we’ve gone throughout history. Insects are so numerous and have existed for such a long time that we can learn a lot about ancient life through sampling archaeological sites for insects.

There is a whole subdiscipline dedicated to studying ancient insects. It’s called “archaeoentomology,” which is kind of a big word, but if you break it down, you get two parts: archaeo-, referencing archaeology, and -entomology, meaning the study of insects. Together, you get the archaeological study of insects. Typically, archaeologists study insects by using scientific techniques to extract them from the soil collected from sites. Archaeoentomologists actually use similar methods to paleoethnobotanists, and both of these sub-fields are encompassed by the umbrella term “environmental archaeology.” 

There are literally millions of different species of insects in the world, but a few are particularly useful to archaeologists, including lice, fleas, bedbugs, flies, and beetles. These insects are important because they tend to live near–or on–humans. They also tend to preserve well in the dirt, unlike some other insects. For example, honeybees have been extremely important to human communities throughout history, but bee remains are rare in the archaeological record because they are fragile and decompose very quickly. 
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One of the reasons that archaeologists study insects is because they can help us reconstruct ancient environments. This relies on the idea that certain insects prefer particular environmental conditions–for example, the stag beetle prefers living in damp, dark forested areas, while the darkling beetle loves dry desert climates. Therefore, if a certain insect species is abundant at a site, archaeologists can extrapolate what the environment was like–for example, if it was wet and rainy, or hot and dry. 

By extension, changes in insect populations can tell us how human activity impacted the insect populations around them. For instance, a team of archaeologists in Greenland sampled soil from both a modern farm and an approximately 700-year-old farm. They compared the presence of insects at each site, and found that modern agricultural practices have significantly decreased the diversity of insect species in Greenland. On the other hand, historical farming practices actually increased biodiversity. 

Studying insects from archaeological sites can also tell us in great detail about invasive species and when they were introduced. Researchers working in Jamestown, Virginia sampled soil from a well that was used in the early 1600s. They found the remains of beetles that are not native to the Americas, and suggest that early European colonists accidentally introduced insect species that ended up causing infestations of their crops. Many of the species that the colonists brought from England in the 17th century are still present in the U.S. today, and sometimes still cause issues. 

Insect remains can also reveal to archaeologists a trove of information about what people ate in the past. Sometimes, archaeologists find direct evidence of people eating insects, which was a super common practice across the world throughout history and in the present day. However, it can often be hard to find direct archaeological evidence of entomophagy, or the consumption of insects.

By Desmond W. Helmore - Manaaki Whenua – Landcare Research, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=72864370

Instead, archaeologists can use bugs as a proxy to find out what kinds of plants people grew and stored. By that I mean, there are many species of insects that like to eat specific plants, which tend to be plants humans also like to eat. The presence of, say, a rice weevil at the archaeological site of an ancient houses signals there was likely rice stored in that house, even if we don’t find the remains of the rice itself. 

For example, at an approximately 800-year-old site in Gran Canaria, Spain, archaeologists found the remains of insect pests in granaries, which are areas where people stored grains. The presence of certain species, including the granary weevil, is known to destroy stores of grain, and this study suggests that the people of Gran Canaria had to deal with this problem regularly. 

Archaeologists can also use insects to learn all about infectious diseases in the past. Many of the most notorious illnesses known to humankind are vector-borne, which means they are transmitted by the bites of insects and other arthropods when they feed on our blood. Think yellow fever caused by mosquitoes, plague caused by fleas, or sleeping sickness caused by tsetse flies. Scientists sometimes refer to insects like lice and fleas as “ectoparasites,” meaning they live outside our bodies, like on our skin and hair, rather than inside of us like other parasites, such as tapeworms. Ectoparasites were extremely common in the past and have existed pretty much in every human community. 

Janice Harney Carr, Center for Disease Control, Public domain, via Wikimedia Commons

For example, archaeologists working at a site in Boston found evidence of lice and other insects, including bedbugs, in historic outhouses dating to the mid-1800s. In 19th-century cities, nearly everyone had fleas and/or lice. As a result, typhus, a bacterial infection spread by fleas, lice, and a few other ectoparasite species, was rampant across New England alongside a host of other infectious diseases like smallpox, tuberculosis, and syphilis. 

In addition to the environment, food, and health, insects can tell us about ritual practices in the past, especially as they relate to funerary traditions. As deceased animals and humans decompose, insects are vital to the process of breaking down flesh and bone. Forensic scientists are experts in identifying decomposition stages, in part by using the presence of insects like flies. Archaeologists borrow from forensic techniques to investigate ancient burials and the circumstances surrounding them; for example, the recovery of certain insects can indicate whether a body was buried, wrapped in a shroud, or left in the open, or some combination. 

For example, archaeologists working in Northern Mexico sampled the remains of a 11th-century individual found in a cave wrapped in many layers of cloth. They found low levels of the pioneer fly, which is usually the first fly species attracted to decomposing remains. They interpreted this as evidence that the corpse was almost immediately bundled in fabric prior to burial. However, the presence of other fly species suggest that the individual was moved later after being buried. The archaeologists believe that this may be related to funeral traditions and religious beliefs of the hunter-gatherers who lived in this region about 1,000 years ago. 

There is so much that archaeologists can learn from ancient insects, like what people ate in the past, what their environment was like, what diseases they got, and how they treated their dead. I hope that, no matter how you feel about bugs, you have come away from this with a nugget of appreciation for their scientific value.

Additional Sources
Historical Bugs: Archaeoentomology - JSTOR Daily 

Insects Associated with Ancient Human Remains: How Archaeoentomology Can Provide Additional Information in Archaeological Studies

State of the art of the funerary archaeoentomological investigations in Italy | Archaeological and Anthropological Sciences

https://www.researchgate.net/profile/Eva-Panagiotakopulu/publication/276886051_Present_and_Norse_Greenlandic_hayfields_-_Insect_assemblages_and_human_impact_in_southern_Greenland/links/55a401df08ae00cf99c8f181/Present-and-Norse-Greenlandic-hayfields-Insect-assemblages-and-human-impact-in-southern-Greenland.pdf ​

This blog post was partially adapted from a YouTube video I wrote with Smiti Nathan for her channel @smitinathan.