A grizzly bear eats a frozen fruits during a hot summer day at Rio de Janeiro's zoo January 13, 2015. According to a local climate institute, temperatures in Rio de Janeiro on Tuesday rose up to 34 degrees Celsius (93.2 degrees Fahrenheit). (Photo by Sergio Moraes/Reuters)

Arnold Schwarzenegger gives a thumbs up as he arrives for the Europe premiere of his new movie 'Terminator: Genisys' in Berlin, Germany, Sunday, June 21, 2015. (AP Photo/Michael Sohn)

Look at the image for long enough and you can make the train change direction simply by thinking about it. Freaky.

A man reacts as health workers help collect a nasal swab sample to test for COVID-19 in Hyderabad, India, Thursday, September 17, 2020. As India’s coronavirus confirmed cases jump by a record 97,894 cases in the past 24 hours, Prime Minister Narendra Modi’s government faced a scathing opposition criticism in Parliament for its handling of the pandemic and a contracting economy leaving millions jobless on Thursday. (Photo by Mahesh Kumar A./AP Photo)

A robin perches on a spade handle in a garden on a rainy day in Lixwm, north Wales. Researchers said this week that when European robins are subjected to human-produced noise, their behaviour changes. (Photo by DGDImages/Alamy Live News)

The Invasion. A quiet street in Macau. Modernization around is quickly changing the city, as documented by Paul Tsui. (Photo by Paul Tsui/National Geographic Travel Photographer of the Year Contest)

Visitors look at a plastinated human body during the “Body Worlds” exhibition by German anatomist Gunther von Hagens at a pavilion of the Exhibition of Achievements of National Economy (VDNKh) in Moscow, Russia on March 24, 2021. Head of Russian Investigative Committee Alexander Bastrykin ordered a probe of the exhibition after it sparked outrage among conservative religious groups and public figure. (Photo by Evgenia Novozhenina/Reuters)

A young Iranian woman walks in Tehran on June 14, 2021, ahead of the June 18 presidential elections. Iran is gearing up for a presidential election on June 18 but many young people are more focussed on the daily struggle to survive and their dreams for the future. Jobs are scarce in a recession-hit economy battered by sanctions, a crisis exacerbated by the region's worst outbreak of the Covid pandemic. (Photo by Atta Kenare/AFP Photo)