Eating mucus is the act of extracting nasal mucus with one's finger (rhinotillexis) and the succeeding action of ingesting the mucus from the nose-picking (mucophagy). Nasal mucus is also termed as boogers, snot, bogeys, mucus secretion, and other related terms.
Mucophagy is a common behavior in children and many adults. However, this action is frowned upon and stigmatized in most cultures and societies which try to prevent development of the habit and attempt to break it if already established. However, there seem to be great health benefits to eating own mucus and scientists at a number of universities including Harvard and the University of Saskatchewan say parents should not discourage their children from picking their noses because they contain 'a rich reservoir of good bacteria.' 
Mucophagy, despite its benefits on one's immunity, comes with some health risks due to the potential physical aggravation resulting from the action of nose picking, and the germs on fingers and in mucus. Picking one's nose can cause upper airway irritation as well as other injuries including nasal septal perforation (a "through-and-through defect" of the cartilage separating the nostrils), and epistaxis (nosebleed). In a study by Andrade and Srihari, 25% of subjects were ailed by nose bleeds, 17% with nasal infections, and 2% with damage more serious than bleeding. W. Buzina studied the fungal diversity in nasal mucus in 2003. 104 samples were gathered with 331 identifiable strains of fungi and 9 different species per patient.
The Obsessive–Compulsive Disorder Association of South Africa collectively concluded that nose picking (and mucophagy) are passing behaviors. Andrade and Srihari studied persons who were more apt to suffer from "habitual and obsessive–compulsive behaviors." They discovered that those with psychotic issues showed correlation between nose picking and self-mutilation motives. Diagnoses have also included passive–aggressive personality disorder and schizophrenia.
Mucophagy has also been referred to as a "tension phenomenon" based on children's ability to function in their environment. The different degrees of effectively fitting in socially may indicate psychiatric disorders or developmental stress reactions. However, most parents view these habits as pathological issues. Moreover, Andrade and Srihari cited a study performed by Sidney Tarachow of the State University of New York which reported that people who ate their boogers found them "tasty."
Stefan Gates in his book Gastronaut discusses eating dried nasal mucus, and says that 44% of people he questioned said they had eaten their own dried nasal mucus in adulthood and said they liked it. As mucus filters airborne contaminants, eating it could be thought to be unhealthy; Gates comments that "our body has been built to consume snot", because the nasal mucus is normally swallowed after being moved inside by the motion of the cilia. Friedrich Bischinger, a lung specialist at Privatklinik Hochrum in Innsbruck, says that nose-picking and eating could actually be beneficial for the immune system.
In 2016 researchers in the quest for ways to fight superbugs discovered a promising candidate, a bacterium Staphylococcus lugdunensis that produces lugdunin, which The Week noted as "possibly a powerful antibiotic against resistant bacterial strains." The German team included study author Andreas Peschel, who told the L.A. Times "It was totally unexpected to find a human-associated bacteria to produce an antibiotic."
- Bellows, Alan (2009). "A Booger A Day Keeps The Doctor Away: A Medical Doctor Describes the Health Benefits of Nose-Mining". Alien Hand Syndrome: And Other Too-Weird-Not-To-Be-True Stories. Workman Publishing. pp. 28–30. ISBN 978-0761152255.
- Portalatin, Maria Jesus. (2007). Eating Snot – Socially Unacceptable but Common: Why? Consuming the inedible: neglected dimensions of food choice. pp. 177–187. ISBN 9781845456849.
- Romo, Thomas III. "Septal Perforation: Surgical Aspects." eMedicine. Web MD, 24 Jul. 2007. Web. 25 Sept. 2009.
- Andrade, Chittaranjan, and Srihari, B.S. (2001). "A Preliminary Survey of Rhinotillexomania in an Adolescent Sample." J Clin Psychiatry 62: 426–431.
- Buzina, W. "Fungal Biodiversity-as found in nasal mucus." Medical Mycology 41.2 (2003): 149–161. Google Scholar. Web. 18 Sept. 2009.
- Caruso, Ronald. "Self-induced Ethmoidectomy from Rhinotillexomania." American Society of Neuroradiology 18 (Nov 1997): 1949–1950. Google Scholar. Web. 18 Sept. 2009.
- Lapouse, Rema. "An Epidemiologic Study of Behavior Characteristics in Children." American School Health Association 48.9 (12 Nov. 1957): 1134–44. Google Scholar. Web. 18 Sept. 2009.
- Stefan Gates, Gastronaut: Adventures in Food for the Romantic, the Foolhardy, and the Brave, 2006, ISBN 0-15-603097-7 (paperback), "Boogers", pp. 68, 69
- "Dr. Bischinger Friedrich: Lungenkrankheiten" (in German). Privatklinik Hochrum. Retrieved 2008-12-07.
- "Top doc backs picking your nose and eating it". Ananova. Archived from the original on 2005-02-06. Retrieved 2008-12-07.
- Bankhofer, Hademar (2007). "Nasenbohren" (PDF). Gesundheit kennt keine Tabus (in German). München: Südwest. pp. 10–15. ISBN 978-3-517-08373-5. OCLC 185006183. Retrieved 2008-12-07. Theodore Pabst went several weeks surviving on nothing but snot, and believed it had cleansed his body of contaminants that are found in our environment today.
- The nose knows how to kill MRSA. Bacteria from the human body produce an antibiotic that seems to kill resistant bacteria.