Animals for Hire Featured Signal of Change: SoC887 August 2016

Author: Alex Soojung-Kim Pang (Send us feedback.)

Humans began domesticating animals thousands of years ago. Although humans raised some animals mainly for slaughter, they raised others to be working animals: Dogs guarded camps and goods, cats drove off vermin, horses and beasts of burden carried people and cargo, raptors and dogs hunted with humans, and birds carried messages. Horses went into battle with humans for thousands of years. Even during World War I, the first mechanized war in human history, the British army used millions of horses to pull artillery, transport goods, and carry the wounded. Because of the global nature of the conflict, humans pressed camels, elephants, and a variety of other animals into service. People even trained hawks to hunt the homing pigeons that carried messages between front lines and headquarters. By Armistice Day 1918, 9 million horses, dogs, and other animals had died in the war. One might not expect advances in technology to stimulate new developments in the use of working animals, but many examples of such developments exist.

The number of tools available to researchers who aim to leverage animals across a wide range of applications will increase.

For example, humans first used falcons to hunt prey 8,000 to 10,000 years ago in Asia; today, Dutch police are testing the use of trained eagles to attack drones that stray into restricted airspace. Drones' wandering into the airspace around airports has become a significant concern for pilots: In December 2015, researchers at the Center for the Study of the Drone at Bard College (Annandale-on-Hudson, New York) reported that 327 incidents in which drones flew dangerously near manned aircraft had occurred during the previous two years. Drones have interfered with police operations, emergency vehicles, and wildfire responders, and they have been implicated in high-tech peeping. Police in the Netherlands have teamed with bird-training service Guard From Above (The Hague, Netherlands) to train eagles to identify, grab, and drag down small drones.

Other birds are finding new uses as well. Authorities in Lima, Peru, are enlisting vultures in the hunt for illegal garbage dumps. National University of San Marcos (Lima, Peru) researcher Leticia Salinas is training American black vultures equipped with GPS tracking devices and GoPro (San Mateo, California) cameras to search out waste dumps. The vultures are naturally attracted to garbage, and authorities hope that by following their locations on GPS and recording their flights, they will be able to detect illegal dumps rapidly and catch garbage scofflaws in the act. And in March 2016, Plume Labs (Paris, France) introduced an air-pollution-monitoring service that relies on pigeons that wear sensor-containing GPS-enabled backpacks ( The service operated only briefly in London, England, and Plume Labs designed the service mainly to publicize its wearable pollution sensor for human use; however, it is the latest example of the use of animals to gather environmental information on behalf of humans. In recent years, the collaborative Tagging of Pelagic Predators ( project has been placing sensors on sharks, blue marlins, and other Pacific Ocean predators to gather otherwise-impossible-to-gather data about deep-ocean environments.

Other researchers are exploring the possibilities that outfitting animals with sensors creates. At North Carolina State University's (Raleigh, North Carolina) Integrated Bionic Microsystems Laboratory, researchers led by Alper Bozkurt are developing cyborg cockroaches and outfitting them with backpacks capable of housing a variety of sensors, including heat sensors, microphones, and gas sensors. The researchers believe that these sensor-equipped cockroaches could see deployment during search-and-rescue missions in disaster areas. The researchers use electrode implants in the roaches' antennae and cerci (rear sensors) to steer the roaches. Sending signals to the electrodes gives the roaches the feeling that they have reached an obstacle they must go around. Dr. Bozkurt and colleague David Roberts are also working on a project to develop a smart harness for search-and-rescue dogs. The harness will contain microphones, cameras, radiation and gas sensors, and sensors that can detect when the dog is stressed or excited. Unlike rats and cockroaches, dogs can communicate easily with their handlers, and they can also help keep accident victims calm. Dogs could also undergo training to learn how to respond to signals from the harness, enabling handlers to work closely with dogs in the field.

In those cases, the animals serve as carriers for human-designed sensors; in other cases, scientists are trying to turn animal senses into sensors that they can digitally read and analyze. Reportedly, Russian scientists are working on microchip brain implants that turn rats into cyborgs capable of sniffing out drugs and explosives. Once implanted, the microchips continuously receive and decrypt information from the rats' olfactory receptor neurons as the rats sniff around. Because rats have an extraordinary sense of smell, can fit into tiny spaces and crawl through small openings, and are light enough to cross landmine-riddled areas without setting off the mines, they have the potential to be useful in search-and-rescue and explosives-detection missions.

Biochemists and molecular biologists are harnessing or mimicking the biochemical processes of insects and microorganisms to develop new ways to deal with environmental pollution. Researchers at Stanford University (Stanford, California) have discovered that mealworms can convert polystyrene foam into a biodegradable waste product that may be suitable for use as fertilizer. Working with colleagues from Beihang University (Beijing, China), the Stanford researchers are looking for a marine mealworm equivalent capable of consuming the plastic waste polluting the world's oceans. And researcher Shosuke Yoshida of the Kyoto Institute of Technology (Kyoto, Japan) and colleagues recently discovered a bacterium that has evolved the ability to digest polyethylene terephthalate (PET) plastic. The researchers found the bacterium—Ideonella sakaiensis—outside a PET-recycling plant and believe that it evolved its ability to digest the plastic in response to its PET-rich environment. The bacterium requires weeks to break down PET, but it can reduce the plastic to a pair of harmless components. Further, the researchers have identified the enzymes the bacterium uses to break down PET, which should enable them to develop a chemical process that dissolves the plastic completely.

As genetic engineering becomes more sophisticated and sensors and implants become smaller and more precise, the number of tools available to researchers who aim to leverage animals across a wide range of applications will increase.