The Aka or Bayaka (also BiAka, Babenzele) are a nomadic Mbenga pygmy people. They live in southwestern Central African Republic and the Brazzaville region of the Republic of the Congo. An ecologically diverse people, they occupy 11 different ecological zones of the Western Congo Basin. They are related to the Baka people of Cameroon, Gabon, northern Congo, and southwestern Central African Republic.
Unlike the Mbuti pygmies of the eastern Congo (who speak only the language of the tribes with whom they are affiliated), the Aka speak their own language along with whichever of the approximately 15 Bantu peoples they are affiliated.
In 2003, the oral traditions of the Aka were proclaimed one of the Masterpieces of the Oral and Intangible Heritage of Humanity by UNESCO. They were featured in the July 1995 National Geographic article "Ndoki: the Last Place on Earth".
A traditional hunter-gatherer society, the Aka have a varied diet that includes sixty-three plants, twenty-eight species of game and twenty species of insect, in addition to nuts, fruit, honey, mushrooms and roots. Some Aka have recently taken up the practice of planting their own small seasonal crops, but agricultural produce is more commonly obtained by trading with neighboring villages, whom the Aka collectively term as Ngandu.
From the Ngandu, they obtain manioc, plantain, yams, taro, maize, cucumbers, squash, okra, papaya, mango, pineapple, palm oil, and rice in exchange for the bushmeat, honey, and other forest products the Aka collect. There are over 15 different village tribes with whom the approximately 30,000 Aka associate.
Fathers of the Aka tribe spend more time in close contact to their babies than in any other known society. Aka fathers have their infant within arms reach 47% of the time  and make physical contact with them five times as often per day as fathers in some other societies. It is believed that this is related to the strong bond between Aka husband and wife.
Throughout the day, couples share hunting, food preparation, and social and leisure activities. The more time Aka parents spend together, the more frequent the father's affectionate interaction with his baby.
The lifestyle of the Aka has been shifted from their traditional customs by European colonialism. The slave trade of the 18th century caused the migration of several tribes into Aka lands. These tribes subsequently became affiliated with the Aka. By the end of the 19th century, the Aka were the major elephant hunters providing tusks for the ivory trade. Affiliated tribes acted as middlemen in these transactions.
From 1910 to 1940, the Aka lands were part of French Equatorial Africa, and nearby affiliated tribes were forced into rubber production by the colonialists. These laborers occasionally escaped into forests inhabited by the Aka, increasing the demand for bushmeat. To meet this demand, the Aka developed the more efficient method of net hunting to replace traditional spear hunting. This caused a change in the social structure of the Aka: net hunting was seen as less physically challenging than using spears to kill game, and so women were encouraged take part in hunting activities.
In the 1930s, the French pressed the Aka to move into roadside villages. However, like the Efé of the Ituri rainforest, most Aka disobeyed and retreated into the jungle, with few joining the new settlements (except for a few villages in Congo-Brazza).
Today, economic pressures have forced the Aka to further deviate from their traditional customs. Many Aka now work in the coffee plantations of neighbouring tribes during the dry season instead of hunting as they would have done, and others have found employment in the ivory and lumber trade.
The World Wildlife Fund of Washington, DC, has worked with the Aka since the 1980s to protect gorilla habitats, minimize logging of forest, and promote other conservation efforts while empowering the Aka and other indigenous peoples.
Their complex polyphonic music has been studied by various ethnomusicologists. Simha Arom has made historical field recordings of some of their repertoire. Michelle Kisliuk has written a detailed performance ethnography. Mauro Campagnoli studied their musical instruments in depth, comparing them to neighbouring pygmy groups such as the Baka Pygmies).
Aka musicians appear on: African Rhythms (György Ligeti, Steve Reich and Pierre-Laurent Aimard, 2003), Echoes of the Forest: Music of the Central African Pygmies (Ellipsis Arts, 1995), BOYOBI: Ritual Music of the Rainforest Pygmies (Louis Sarno, 2000) and Bayaka: The Extraordinary Music of the BaBenzele Pygmies (Louis Sarno, 1996).
Song from the Forest by German director Michael Obert tells the story of American Louis Sarno who has lived among the Bayaka pygmies in the central African rainforest for 25 years and travels with his son, 13-years-old pygmy boy Samedi, to New York City. The film premiered at the International Documentary Film Festival Amsterdam 2013  where it was honored with the Award for Best Feature-Length Documentary.
Other Pygmy groups
Anthropologists studying the Aka
- Seize the Dance! BaAka Musical Life and the Ethnography of Performance by Michelle Kisliuk (Oxford University Press, 2000).
- Song from the Forest -- My Life Among the Ba-Benjellé Pygmies by Louis Sarno (Houghton Mifflin 1993).
- The Aka call themselves Baaka (which means Aka people) and their language Aka. In the Lobaye region, these become Bayaka and Yaka due to epenthesis whenever there is no consonant starting a syllable. In Bagandu, the forms are Biaka and Diaka, and in the Sangha River region, Babenjelé and Aka. (It is not clear if these are endonyms or exonyms.) The names in Sango and Lingala are Ba(m)benga and Beka. (Duke, 2001, Aka as a Contact Language.)
- Michael Nichols (2001). "Gallery: Ndoki: The Last Place on Earth".
- Barry Hewlett (1991). Intimate Fathers: The Nature and Context of Aka Pygmy Paternal Infant Care. University of Michigan Press. Full chapter 2
- Johnson ED, Gonzalez JP, Goerges A. "Filovirus activity among selected ethnic groups inhabiting the tropical forest of equatorial Africa". Transactions of the Royal Society of Tropical Medicine and Hygiene 1993;87:536-538.
- "Congo Basin: Protecting Africa's Tropical Forests: People". World Wildlife Fund.
- "Michelle Kisliuk and Justin Mongosso: The BaAka of Central Africa".
- http://songfromtheforest.com/ Song From the For-est
- http://www.hollywoodreporter.com/review/song-forest-idfa-review-659585/ Hollywood Reporter, Review Song From the For-est
- http://www.indiewire.com/article/review-gorgeous-song-from-the-forest-tracks-how-louis-sarno-joined-a-pygmy-tribe-started-a-family-and-returned-to-new-york/ Indiewire, Review Song From the Forest
- http://www.screendaily.com/news/song-from-the-forest-wins-at-idfa/5064163.article/ Screen Daily, Song From the Forest wins IDFA Award
- http://www.idfa.nl/industry/press/29-november-song-from-the-forest-wins-the-vpro-idfa-award-for-best-feature-length-documentary.aspx/IDFA, Song From the Forest wins IDFA Award
- Article: "Are the men of the African Aka tribe the best fathers in the world?"
- Aka Pygmies of the Western Congo Basin
- Fieldwork about Baka, Aka and other pygmy groups
- African Pygmies with photos, music and ethnographic notes
- www.songfromtheforest.com (SONG FROM THE FOREST official website)