At first glance it sounds like a scene from a futuristic film: a wild crow on a Swedish street picks up a cigarette butt, flies to a strange box, drops the trash into a slot—and a small piece of food pops out of a dispenser. That’s exactly the principle behind Corvid Cleaning, a startup testing a device in the Swedish city of Södertälje that swaps litter for food. The goal is to reduce the amount of trash on the streets and save cities money on cleaning—using extraordinarily intelligent birds from the corvid family as the “workforce.”
How the “crow vending machine” for trash works
The device developed by the startup is essentially a special trash bin connected to a food dispenser. A crow or another corvid flies to the box, drops a cigarette butt or a small piece of litter into the opening, and a sensor inside evaluates whether it really is the type of waste the system is set up to recognize. If it is, the machine releases a small portion of feed as a reward. If not, it stays silent—no food, no incentive to continue.
The startup is thus leveraging a simple principle of positive reinforcement. First, birds are attracted with food placed around the device; over time, the feed is moved closer to the opening and eventually into it. The bird learns that the reward comes only when it drops the correct item inside. The system is designed to distinguish cigarette butts from pebbles or leaves and to dispense a reward only when the bird “does the work.”
Why cigarette butts are such a problem
Cigarette butts have long been the most widespread form of plastic litter in the world. The filter contains plastics, nicotine, heavy metals, and other toxic substances that gradually leach into soil and water. It’s estimated that trillions of discarded butts circulate worldwide, taking years to break down.
In Sweden, cigarette butts make up about 62% of all street litter, and estimates suggest more than a billion butts end up on the country’s streets each year. The city of Södertälje spends around 20 million Swedish kronor annually on street cleaning—at the current exchange rate, roughly €1.8 million. The startup estimates that if birds took over a substantial part of this work, the cost of collecting cigarette butts could be reduced by as much as three quarters.
Smart crows as ideal “employees”
The startup didn’t choose crows by accident. Corvids—crows, ravens, jackdaws, and magpies—are among the most intelligent creatures on the planet. Multiple experiments have shown that some crow species can solve multi-step tasks, use tools, and plan ahead at roughly the level of a 7- to 10-year-old child.
Corvid Cleaning founder Christian Günther-Hanssen explains that crows already live in close proximity to people— in cities and residential areas. They’re used to rummaging through trash in search of food scraps. From the startup’s perspective, it’s a logical next step to offer them a “fairer deal”: instead of risky scavenging in bins, they get a guaranteed reward for bringing a specific type of waste to a designated place. It’s also expected that once some birds learn to use the system, others will quickly pick it up by observing them.
How much can a city realistically save?
With conventional street cleaning, collecting a single cigarette butt costs Swedish municipalities an estimated €0.07–€0.18, depending on labor costs, equipment, and other expenses. The startup claims that if crows collected the butts, costs would drop to about €0.02 per piece, since the only “wage” is a small amount of feed and basic maintenance of the device.
At a million butts a year, the difference between €0.18 and €0.02 quickly turns into tens or hundreds of thousands of euros; at the real volumes seen in large cities, it can even reach millions. According to The Guardian, a successful rollout of the pilot project in Södertälje could deliver savings of roughly 75% on costs associated with collecting cigarette butts.
It’s not just about money: an environmental and educational effect
While the financial savings sound attractive, the project has another dimension as well. Highly visible devices where people can literally watch birds trading trash for food also work as a form of “eco-shaming.” Many passersby find it bizarre that we can teach crows to clean up after humans—yet we can’t persuade some smokers to put a butt in a bin. That’s one of the ideas city representatives emphasize in interviews.
The presence of such a machine can raise awareness that a cigarette butt is not “a tiny thing that will disappear,” but a plastic filter soaked with toxins. Ideally, the project would lead to fewer discarded butts in the first place—and the birds would have less work to do.
Bird health and ethical dilemmas
On the other hand, there’s the legitimate question of whether it’s appropriate to deliberately encourage wild birds to handle toxic waste. Cigarette filters contain nicotine, heavy metals, and other substances that can be harmful with long-term contact. The startup’s founder and municipal authorities therefore stress that this is a pilot project, and that monitoring the birds’ health is crucial.
The advantage is that crows don’t swallow the butt—they simply grab it with their beak and carry it to the device. However, whether this could still cause micro-exposures that accumulate over time hasn’t been fully mapped scientifically yet. The startup therefore presents the project as a complementary measure alongside existing approaches, not as the only way to tackle cigarette litter.
From a university experiment to a city startup
The idea of a “vending machine for crows” isn’t entirely new. Back around 2008, American inventor Joshua Klein presented a device in a TED talk that taught crows to collect coins in exchange for food. Later, several prototypes of similar machines emerged in different European countries, focused on various types of waste.
Corvid Cleaning, however, is among the first projects to try to move such an experiment into a real urban environment and tie it to concrete figures on street-cleaning costs. In 2024, the startup became the subject of a case study in the academic journal Emerging Economies Cases Journal, where it is analyzed as an example of a “learning organization” that learns from experiments with both animal and human behavior while trying to find a sustainable business model.
Can such a system be expanded to other cities?
The project’s authors themselves point out that involving birds in city cleaning is not a universal solution. Oversight of animal health, maintenance of the devices, and the need for long-term testing mean Corvid Cleaning won’t become a “miracle cure” for littered streets. Still, the project can have strong inspirational value—it shows that technology and natural animal behavior can be linked in a creative way.
In theory, similar machines could be adapted for other types of waste or other bird species, for example pigeons in major cities. But that runs into additional questions—from disease transmission to whether it’s ethical to train animals to do work that, in reality, humans should stop creating in the first place.
What such a project could mean for countries like Slovakia
Even if the Swedish experiment may seem far removed from our reality, it touches on an issue that’s relevant in Slovakia as well: how to motivate people not to leave litter “just lying around” in nature or on the street. The bottle deposit-return system showed that when a clear economic incentive is set, the number of discarded bottles in public spaces drops significantly.
A project that “pays” animals with food for litter works in a similar way—except that instead of a person bending down to pick it up, a crow does. In terms of raising awareness, similar art-and-technology installations could also work in Slovakia as a powerful symbol: if we can teach wild birds to collect cigarette butts, why can’t we learn basic decency ourselves?
Video: crows at work in a Swedish city
The following short video (in English) shows wild crows in Södertälje collecting cigarette butts and exchanging them for food in Corvid Cleaning’s device:
Where the project could go next
In the coming years, it will likely become clear whether the experiment with crow vending machines for litter will expand to other cities or remain more of a symbolic project aimed at drawing attention to cigarette waste. Even today, however, it’s clear that it connects several strong trends: growing pressure to reduce plastic waste, the search for savings in public budgets, and an effort to change how we perceive animal intelligence.
Even if it ultimately turns out that stricter fines for tossed butts and extensive smoker education are the best solutions, the Corvid Cleaning project already shows that environmental innovation doesn’t always have to be about new apps or algorithms. Sometimes it’s enough to build a smart device, understand the behavior of other species, and offer them a fair deal: you help me, and I help you.
Sources
- Paige Bennett: Swedish Company Trains Crows to Clean Up Cigarette Butts – EcoWatch
https://www.ecowatch.com/crows-cigarette-butts-sweden.html - Trash birds: A startup in Sweden is recruiting crows to do our dirty work – Earth Touch News
https://www.earthtouchnews.com/discoveries/innovation/trash-birds-a-startup-in-sweden-is-recruiting-crows-to-do-our-dirty-work/ - Swedish firm deploys crows to pick up cigarette butts – The Guardian
https://www.theguardian.com/environment/2022/feb/01/swedish-crows-pick-up-cigarette-butts-litter - Jashim Uddin Ahmed, Israt Laila, Asma Ahmed: Corvid Cleaning – Deploys Crows to Clean Up Cigarette Butts in Sweden – Emerging Economies Cases Journal
https://journals.sagepub.com/doi/10.1177/25166042241296275
Jana
I like turning curiosity into words, and writing articles is my way of capturing ideas before they slip away — and sharing them with anyone who feels like reading.
