In the mid-2010s, quokkas earned a reputation on the internet as "the world's happiest animals" and symbols of positivity, as frontal photos of their faces make them appear to be smiling (they do not, in fact "smile" in the human sense; this can be attributed to their natural facial structures). Many photos of smiling quokkas have since gone viral, and the "quokka selfie" has become a popular social media trend, with celebrities such as Chris Hemsworth, Shawn Mendes, Margot Robbie, Roger Federer and Kim Donghyuk of iKON taking part in the activity. Tourist numbers to Rottnest Island have subsequently increased