Animals Pets 10 Fascinating Facts About Chickens By Katherine Martinko Senior Writer University of Toronto Katherine Martinko is a writer and expert in sustainable living. She holds a degree in English Literature and History from the University of Toronto. our editorial process Twitter Twitter Katherine Martinko Updated November 24, 2020 Treehugger / Christian Yonkers Share Twitter Pinterest Email Animals Wildlife Pets Animal Rights Endangered Species Chickens long ago were seen as exotic, fascinating birds. These descendants of exotic Asian jungle fowl were once revered for their ferocity and intelligence. But then, we humans began eating them in ever-larger quantities until we reached the point where we are now, with 23.7 billion chickens that live primarily on commercial egg and poultry farms. Chickens have been a part of human lives for millennia, and yet they are one of the most misunderstood, if not ignored, species on Earth. From stellar math skills to ears that tell their eggs' color, take a look at these crow-worthy chicken facts. 1. Chickens Are a Subspecies of the Red Jungle Fowl That Hails From Southeast Asia Lip Kee / Flickr / CC BY-SA 2.0 The red jungle fowl (gallus gallus) inhabits the edges of fields, scrubland, and groves of southern Asia and India. They also have truly wild populations in Kauai and feral populations elsewhere in the United States. The red jungle fowl domestication was well established over 4,000 years ago. They look very similar to common domestic chickens, though thinner, but have white patches on the side of their head and grey legs. 2. Domestic Chickens Are Similar to Their Wild Counterparts Intense selective breeding has not caused cognitive changes in chickens. Dogs and wolves, as a contrast, have diverged significantly due to domestication. Lower aggression toward predators occurred in many species as they were domesticated, though not chickens. Some chickens are more combative even than red jungle fowl. Red jungle fowl and chickens also react to the scent of predators, while most birds do not. 3. Chicken Beaks Are Highly Sensitive to Touch With numerous nerve endings, the beak is used to explore, detect, drink, preen, and defend. Scientists believe that the beak nerve structures have a sensitivity similar to that of a human hand. These nerve endings mean that when a bird is de-beaked, as often happens in industrial farming, it experiences great pain, sometimes for months, which changes its behavior. The chickens eat less, have poorer feather condition from not preening, and spend less time pecking. 4. Chicken Combs Are Bright Beacons of Health and Fertility Simon McGill / Getty Images Combs, the red fleshy appendage on the top of a chicken's head, tells a lot about a chicken's fertility. In hens, the larger the comb, the more eggs she lays. In males, the deeper the red of the comb, the more fertile he is. Scientists believe there is a relationship between comb size and fertility, but the research is mixed. Hens choose roosters with larger, redder combs. A healthy chicken has a bright, red comb, unless it is a breed with a dark comb, like silkies. If it looks smaller, paler, drier, swollen, or scabbed over, the chicken may be ill. Chickens can even get frostbite on their combs. 5. Chickens Have Finely Tuned Senses Chickens can see long distance and close-up at the same time in different parts of their vision. They can see a broader range of colors than humans. They can hear at a wide range of frequencies. They possess well-developed senses of taste and smell. Chickens bred for egg-laying can even orient to magnetic fields. Similar to a compass, they have magnetoreceptors in their beaks. This helps chickens navigate back to food sources from their roosting areas. Chickens that undergo beak trimming must stay closer to their food sources to avoid losing their way back. 6. Chickens Don't Need a Rooster to Lay Eggs A rooster isn't needed for a hen to start or continue laying eggs. Much like in humans, once a hen reaches puberty, they release eggs regularly. Each egg takes around 24 hours to form before the chicken lays it. Once the egg is laid, the development of a new egg starts approximately 30 minutes later. Chickens lay fewer eggs in extreme heat. While they don't need a rooster to lay eggs, chickens need at least 14 hours of daylight per day to lay eggs. This is nature's way of ensuring that chicks are hatched in the spring, and then have the summer and fall to mature. 7. Hens Talk to Their Eggs SimonSkafar / Getty Images The chicks inside the eggs peep back as they near hatching. The chicks hear sounds after the 12th to 14th day of incubation. The hens use a combination of humming and clucks when talking to the eggs, which helps speed prenatal brain development in the chick. Researchers have found that the hen's small talk also helps the chick imprint on the correct hen. Chicks instinctively move toward the source of the sound they heard while in the egg. 8. Chickens Are Surprisingly Good at Math Three-day-old chicks can perform basic arithmetic and discriminate quantities, opting to explore a larger set of balls when they observed objects transferred from one location to another. Not only that, but a chick's math abilities may be better than a human toddler's. In addition to simple addition and subtraction, chicks can even identify ordinal numbers (like third or fifth). Researchers tested ordinal abilities by training chicks with food rewards to pick the object in the fourth position. The chicks chose the object in the fourth position in later tests, regardless of spacing and the number of items. 9. Chickens Have Ears That May Tell You the Egg Color They Lay Luis Martinez / Eyeem / Getty Images In most breeds of chicken, their earlobe color indicates the color of the eggs they will lay. Chicken earlobes are fleshy, similar to wattles and combs, and are found on either side of their head near their ear holes. Dark-colored or red earlobes generally mean the hen will lay brown eggs. White earlobes often correlate with white eggs, while blue or green earlobes mean blue or green eggs. 10. Chickens Can Exercise Self-Control In an experimental setting, chickens were given a choice between a two-second delay with six seconds of access to food versus a six-second delay with 22 seconds of access to food. The hens waited for the longer reward, “demonstrating rational discrimination between different future outcomes while employing self-control to optimize those outcomes.” Self-control usually doesn't appear in humans until age 4.