Giant panda Meng Meng plays on a tree at a Siberian tiger-breeding base in Changchun, China on December 10, 2015. (Photo by Xu Chang/Xinhua Press/Corbis)
In this Wednesday, May 23, 2012 photograph, a young deer and a cat share a moment in Feench village near Jodhpur, Rajasthan state, India. (Photo by AP Photo)
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.
Raccoon Fritzi eats at the home of veterinarian Mathilde Laininger in Berlin, Germany, January 27, 2022. She cares for four raccoons that can no longer be released into the wild. Raccoon Fritzi has an Instagram account with ten thousand followers. (Photo by Hannibal Hanschke/Reuters)
A cat meows in it's owner's bag after fleeing from Kiev in Ukraine to Romania, following Russia's invasion of Ukraine, at the border crossing in Siret, Romania, March 10, 2022. (Photo by Clodagh Kilcoyne/Reuters)
A dog stands next to the body of an elderly woman killed inside a house in Bucha, outskirts of Kyiv, Ukraine, Tuesday, April 5, 2022. (Photo by Felipe Dana/AP Photo)