English singer and songwriter Dua Lipa performs during the Brit Awards 2021 at the O2 Arena, London, Tuesday, May 11, 2021. (Photo by Ian West/PA Wire via AP Photo)
A boy stands near the rotting carcass of a camel that that died of hunger which people had burned to stop the bad smell, in Belif, Garissa county, Kenya on Sunday, October 24, 2021. (Photo by Brian Inganga/AP Photo)
People in colorful costumes perform acrobatics for drivers waiting at red lights in Nairobi, Kenya on February 20, 2024. (Photo by Gerald Anderson/Anadolu via Getty Images)
Opposition activist Marcelin Myrthil AKA Arab holds a machete during a protest against the government and calls for the resignation of Prime Minister Ariel Henry, in Port-au-Prince, Haiti on February 5, 2024. (Photo by Ralph Tedy Erol/Reuters)
Drinkers celebrated on the last Friday before Christmas in York, United Kingdom on December 18, 2020. Black Eye Friday, affectionately named for its tendency to prompt drink-fuelled punch ups as the Christmas cheer spills over, has been dampened this year by the global coronavirus pandemic shutting bars and banning socialising. (Photo by Nb press ltd)
In animals, yawning can serve as a warning signal. For example, Charles Darwin, in his book The Expression of the Emotions in Man and Animals, mentioned that baboons yawn to threaten their enemies, possibly by displaying large canine teeth. Similarly, Siamese fighting fish yawn only when they see a conspecific (same species) or their own mirror-image, and their yawn often accompanies aggressive attack. Guinea pigs also yawn in a display of dominance or anger, displaying their impressive incisor teeth. This is often accompanied by teeth chattering, purring and scent marking.
The first female attack helicopter pilot of Türkiye's Atak helicopter, Deputy Commissioner Özge Karabulut, undisclosed location, Türkiye, January 6, 2022. (Photo by Anadolu Agency via Getty Images)
A festival goer spins a light strip as she dances to electronic music in front of the Belleville stage during the 45th edition of the Paleo Festival, in Nyon, Switzerland, 24 July 2022. The Paleo is the largest open-air music festival in the western part of Switzerland. (Photo by Valentin Flauraud/EPA/EFE)