Fuzz: When Nature Breaks the Law (2021) is the seventh New York Times bestselling book written by American popular science writer Mary Roach. In Fuzz, Roach takes on the issue of human-animal conflict, ranging from deadly bear attacks to falling trees and gulls destroying flower arrangements. Simultaneously humorous and informative, Roach explores the organized efforts to solve these problems while raising the larger philosophical questions of coexistence and the value of life.

Mary Roach is known for her blend of research and humor in her writing. Originally a writer for periodicals, she has focused on popular science books since she published Stiff: The Curious Lives of Human Cadavers in 2003. Fuzz was included in many 2021 “best of” lists and was longlisted for the 2022 Andrew Carnegie Medal for Excellence in Nonfiction.

This guide refers to the 2021 Kindle edition, published by W. W. Norton & Company.

Summary

Content Warning: The source material discusses violence against animals.

From the title, Fuzz: When Nature Breaks the Law, it is clear that Mary Roach is setting up an examination of the age-old conflict between humans and nature. Animals have no conception of human laws, so she looks at modern attempts to prevent, mitigate, or eliminate animal threats to humans.

The first few chapters deal with human deaths caused by animals, such as bears, cougars, elephants, and leopards. The author attends a training for wildlife officers to distinguish between victims of bear and cougar attacks. The details in the first chapter are gory, emphasizing how human-animal conflicts can be quite serious. The main lesson she takes away is that understanding bear behaviors can help a person who inadvertently confronts one. While human instinct may make someone want to turn and run, they should fight that impulse as it may engage the animal’s predatory behavior and make the situation worse.

The second chapter explores why conflicts between bears and humans are increasing. People have moved into bears’ habitats, and with people comes garbage. Garbage attracts all kinds of animals, including bears. Human behavior complicates the solutions, as enforcement of fines for not properly securing garbage can be a sociopolitical issue. Building codes that prohibit door handles giving easy access to bears are often ignored or not enforced. Bears that learn to associate human homes with plentiful food often enter neighborhoods repeatedly, and they are sometimes killed. This can cause public outrage, but officials face a dilemma when the same people who protest do not want to follow preventative steps to deter bears. Translocation is sometimes offered as a solution, but it is expensive, largely ineffective, and creates different problems.

People in India face similar issues with elephants. Elephants are intelligent—capable of figuring out how to get past electric fences—and dangerous because of their size. It is illegal to kill wild animals in India unless the government has officially declared a particular animal a pest, so efforts to mitigate harm from elephants are often information-based, teaching villagers to modify their behavior. In villages where leopards have killed people, villagers sometimes do revenge killings; however, some of their anger is toward the government for not enacting programs that would mitigate the deadly attacks, such as having school buses and better access to hospitals.

Nature causing accidental human deaths is covered in several chapters, ranging from tree branches falling on people, the toxicity of certain plants, and animals colliding with cars and aircraft. Plants are the outliers because they are only deadly if a person uses them with that intent. For example, consuming excess castor beans (the source of abrin) or even rosary peas (the source of ricin) may only cause gastric distress; it takes more effort and knowledge to render them lethal. Militaries, including that of the United States, have experimented with using these phytotoxins on enemy armies but did not find much success. Like animals, people revere tall, old trees and want to save them, but branches can fall off. Blowing up the dangerous top third of a tree makes it safer if it’s dying, but sometimes, people protest the action. Getting into a plane’s engines is deadly for birds and damaging to planes, but it can also be dangerous for people if the engines fail. Consequently, the FAA and NASA study how to keep birds away from runways and launch pads. Deer are an even bigger concern on roads and runways because of their size. Researchers have learned that animal brains have not evolved to estimate the speed and distance of objects that move as fast as cars and planes. Scaring them away well before impact is the goal and includes solutions like lights that shine on a car’s grill.

Several chapters are dedicated to nuisance animals and pest control. Birds, rodents, and invasive species are featured in these chapters. Decades ago, people used bombs to kill problem birds that ate their crops. Despite the millions of birds killed, it did not reduce populations because of compensatory reproduction, wherein remaining animals no longer have as much competition for resources and reproduce more readily. Frightening devices startle birds, but only for a few minutes. Some companies have devised drones that mimic falcons, but the services are expensive. The Vatican has hired a company that uses lasers to deter birds from destroying their floral displays. The US Navy Base on Midway Atoll tried clubbing albatrosses but stopped when it was not only found ineffective but demoralizing for the sailors. Effigies of dead birds seem to work the best, but it is not practical to hang them where the public might see them.

New Zealand offers an interesting case study in dealing with invasive species. Many of the island nation’s native animal and plant species have been destroyed by the introduction of non-native animals, such as stoats and brushtail possums. The government mandates that eradicating these invasive species be done in the most humane ways possible. That means that an animal should be rendered irrevocably unconscious before death, if not killed instantly. Traps that target their heads and poisons that cause unconsciousness have proven to be the most humane and effective. However, the author questions how humans decide which lives to value over others, citing how prejudices conceal double standards and irrational decision-making.

Cutting-edge pest control technology uses genetic modification in target species. Scientists are testing this on mice, modifying them so that they only produce male offspring. Over generations, the population will dwindle without the use of poisons, traps, or bombs. The plan is to install the mice on an island so they are isolated and do not get out into the wild. There are drawbacks, however, because they will need a large number of these gene-drive mice on the island, temporarily exacerbating the rodent problem. There are also several unknowns, such as whether the local mice will want to reproduce with the new mice and what might happen if the gene-drive mice escape the confines of the island.

Throughout the book, the author poses philosophical questions about human-animal conflict, namely how we decide which species to save, which to ignore, and which to kill. Roach believes that peaceful coexistence is or can be an option if humans alter behaviors and perceptions about living in the natural world.