Student Rabindra Bharati University celebrates the Holi festival, Color Festival on February 26, 2018 in Kolkata, India. Holi, the popular Hindu spring festival of colours is observed in India at the end of the winter season on the last full moon of the lunar month, and will be celebrated on March 1 this year. (Photo by Debajyoti Chakraborty/NurPhoto via Getty Images)

A golden lion tamarin monkey holds its newly born baby at a zoo in Jerusalem, Thursday, March 22, 2018. Golden lion tamarins are among the rarest animals in the world, according to the World Wildlife Fund. It is listed as endangered according to the International Union for Conservation of Nature. (Photo by Sebastian Scheiner/AP Photo)

Palestinian bedouin shepherds pull their lambs into the water to wash them, in Gaza City, on April 29, 2016. Every year before the beginning of the summer, shepherds wash their herds in the sea. (Photo by Mohammed Abed/AFP Photo)

People carry lychee for sale on a motorbike on a street in Luc Ngan, Bac Giang province, Vietnam, 22 June 2016. Lychee output in Bac Giang province is expected to reach 130,000 tonnes this year. China is still Vietnam's main lychee export market so far, buying around 60 percent of the annual crop, according to official reports. (Photo by Luong Thai Linh/EPA)

A photographer in Somerset, South West England captured the mating rituals of toads as several males attempt to mate with one female all at once. (Photo by John Waters/NPL)

Performers dressed as Pikachu, a character from Pokemon series game titles, march during the Pikachu Outbreak event hosted by The Pokemon Co. on August 10, 2018 in Yokohama, Kanagawa, Japan. A total of 1, 500 Pikachus appear at the city's landmarks in the Minato Mirai area aiming to attract visitors and tourists to the city. The event will be held through until August 16. (Photo by Tomohiro Ohsumi/Getty Images)

A woman touches a robot at the 2018 World Robot Conference in Beijing on August 15, 2018. The conference will be held from 15 to 19 August and will include a conference on robotics, an exhibition and a robot competition with the participation of robotics enterprises to showcase their robot products. (Photo by Wang Zhao/AFP Photo)

Iraqi women practice at the sports club in Diwaniya, Iraq on November 10, 2018. On the blue mats of the al-Rafideen Club in the conservative city of Diwaniya, some 180 km (110 miles) south of Baghdad, some 30 female wrestlers, some still wearing headscarves, train three times a week. When a big competition comes up, they train every day. (Photo by Alaa Al-Marjani/Reuters)