Pupils from St Teilo’s Catholic Primary School in Tenby, South Wales, perform a scene from their Nativity play in the second decade of December 2023. The three kings, played by Jack Rigby, Santos Basilnomo and Tommy Leggett, pretended to follow a star on South Beach, a stone’s throw from the school. (Photo by Joann Randles/Cover Images)
Lola Aylmer, 25, stands inside the artist Gemma Anderson-Tempini's infinite laundry mirrored room, which is part of a transformed Victorian house, in Leeds, UK early November 2023. (Photo by South West News Service)
A squirrel and lizard both refuse to give way in an unlikely standoff on a wall in Mohali, India in the first decade of February 2024. (Photo by Anuj Jain/Solent news)
A Australian green tree frog wearing a small turtle as a hat, keeping its head dry during its swim in Padang West Sumatra, Indonesia in May 2023. The Australian green tree frog grows up to 11 centimetres tall, the males being smaller that the females. They can live to the age of 25 and their colour alters between green, brown and blue depending on their mood. (Photo by Yan Hidayat/Media Drum Images)
American model Kendall Jenner attends the Academy Museum Gala fundraiser at the Academy Museum of Motion Pictures in Los Angeles, California, U.S., October 19, 2024. (Photo by Mario Anzuoni/Reuters)
A wounded Palestinian man awaits medical attention at Khan Yunis' Nasser hospital in the southern Gaza Strip on June 19, 2025. (Photo by AFP Photo/Stringer)
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.