This week I found myself thinking about the relationship between worms and what we think of as food waste. I was reminded about my grandfather’s garden and how he used to manage his food waste. He composted his food waste but he was fortunate enough to have his own garden which was also home to a pile of brown gunk called a compost heap. Like most compost heaps, this pile would have been home to many critters who helped to break down the bits of food waste making them into potent and useful fertilizers. This process is called vermicomposting. According to NC State University:
“Vermicomposting is a process that relies on earthworms and microorganisms to help stabilize active organic materials and convert them to a valuable soil amendment and source of plant nutrients.”
Not only does vermicomposting create highly nutritious fertilizer that has far lower CO2 emissions than traditional composting methods, worms presence and poo also increases soil retention and lowers its toxic heavy metals. Conceptually I find this process intriguing. These worms are an essential actor in a multispecies production cycle that includes worms, humans, and other co-composting organisms. But how does it work? How do worms turn food into fertilizer?
Worms and The Labour of Decomposition
Worms use the tiny bristles on their bodies, to move themselves through soil and scraps of food found in a compost heap. Their burrowing habits create air pockets that help other organisms, like bacteria and fungi, opportunities to thrive. The worms also use their tiny mouths at the front end of their body to steadily eat scraps of food, like banana or potato peels. They eventually excrete this material giving those smaller organisms the opportunity to break it down further.
There are over one million species of worms on earth. Ecologists consider worms a keystone species as they play a crucial role in keeping ecosystems alive and healthy. They eat and poop up to one-and-a-half times their own weight a day. Worms determine whether the goods that they encounter are actually food by using cells inside of their body and in their skin that tell them whether it tastes or smells good or not. Their bowel movements result in what we call ‘worm castings’ which are capable of increasing the amount of key nutrients by up to five times compared to the surrounding soil.
Earthworms are perhaps the most well known, but other species, like Tiger Worms and European Nightcrawlers, are known in the ‘composting scene’ for being particularly effective at turning food waste into compost. That is because these species prefer to live on top of soil where they feed on decaying material.
According to research done by Adi and Noor, worms, like me, love coffee. And while my coffee consumption mostly results in reaching deadlines, worms can turn coffee grounds in higher-quality vermicompost with twice the amount of Nitrogen compared to kitchen waste without coffee grounds. So our food waste doesn’t have to be waste at all but can become food for worms who, when they are done working with it, provide the power to nourish more food.
Interestingly, specific forms of vermiculture are being tested where worms help break down human waste in flushless toilets in India, Uganda, and Myanmar, which further connects the bodily processes of humans and worms. According to Furlong and colleagues, who researched one such a trial in India, worms offer a helping hand in improving pit latrine toilets. These are called Tiger Toilets, Wormlets, or, somewhat more official, Vermifiltration Toilets. These toilets use worms to not only turn human poop into the far more useful worm poop, but in this process they also reduce pathogens and make the toilets less likely to flood as worms effectively aerate and break down the waste water.
Vermicomposting and its potential for cities reminds me of the Animal Turn episode with Catherine Oliver where she spoke about Urban Metabolism. Bodily processes play crucial roles in circulating material as both worms and humans consume and produce food. Humans’ urban food waste has the potential to become food for worms who, after having worked through it, can help to nourish new food.
But what if, like me, you don’t have a garden? Can you still participate in this multispecies endeavour?
Wormeries are becoming increasingly popular in cities. Unlike a compost heap, wormeries are containers where worms are bred and kept, often for the purposes of creating compost. If you wanted to start a wormery in your kitchen you would need a sealable container. This container would act as the worms’ office. It would need to be filled with bedding material such as shredded paper and cardboard. After this, it’s time to introduce your co-composters. To sustain your wormery, these worms then need food scraps that have been chopped up into small pieces since they are slightly picky eaters as they’ll prefer to eat bite-sized pieces. Once you put the lid on, all you need to do to keep it going is to just add some more bits of food waste from time to time.
The Ethics of Using Worms
However, as I mentioned earlier, this also raises other questions about nonhuman workers. Of course, these worms just live their lives, but vermicomposting, especially when it is done is the confines of a small container, essentially turns worms’ existence into labour for our purposes. We see this tension in other contexts where animals’ work has been used to clean up human waste. This includes training crows to collect cigarette butts in exchange for treats, using rats to keep sewage pipes clean by eating fatbergs, and in using specific bacteria that help filter sewage water.
The big questions then become, what are the ethics of using animals to do work for us and what does it say about how we value nonhuman lives?
I don’t know the answers to these questions but some scholars are starting to think more seriously about the relationship between animals and labour. Scholars such as Kendra Coulter have put forward a vision of creating humane work for humans and animals. Check out her website humanejobs.org to learn more. Because it is imperative that we take time to think about how we work with animals and what is fair to expect from them.
I’d like to end this animal highlight with a poem from Danusha Laméris titled “Feeding the worms.” He writes:
“Ever since I found out that earth worms have taste buds all over the delicate pink strings of their bodies, I pause dropping apple peels into the compost bin, imagine the dark, writhing ecstasy, the sweetness of apples permeating their pores. I offer beets and parsley, avocado, and melon, the feathery tops of carrots.
I’d always thought theirs a menial life, eyeless and hidden, almost vulgar—though now, it seems, they bear a pleasure so sublime, so decadent, I want to contribute however I can, forgetting, a moment, my place on the menu.”
Herre de Bondt has done research on rats in Amsterdam, crows in Tokyo, and gulls in The Hague. His work has now brought him to London where his PhD project is concerned with urban bird feeding practices. From hanging up fatballs for chirpy robins to tossing seed to flocks of ‘flying rats’, Herre is determined to investigate the inherently multispecies practice of bird feeding. He is particularly interested in the ways non-human animals inform and shape the contemporary city in collaboration with – and in defiance of – humans.
You can connect with Herre via Twitter (@HerreBondt).Learn more about our team here.
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