Students from St Andrews University indulge in a tradition of covering themselves with foam to honour the “academic family” on the lower college lawn on October 23, 2017, in St Andrews, Scotland. (Photo by Jeff J. Mitchell/Getty Images)

A woman dressed up for Halloween travels on a Metro train in São Paulo, Brazil on October 30, 2017. (Photo by Cris Faga/Rex Features/Shutterstock)

A zoo staff feeds crocodiles as visitors look on at the Malabon Zoo in Malabon City, north of Manila, Philippines 21 December 2017. Wearing Santa Claus hats for the upcoming Christmas season, owner Manny Tangco (R, holding megaphone) and some select animals gave visitors a tour of the 28-year-old zoo. (Photo by Rolex Dela Pena/EPA/EFE)

Dutch driver Hans Jos Liefhebber on his KTM drives next to a seal during the fifth stage of the 2018 Dakar Rally, between San Juan de Marcona and Arequipa, on the beach of Puerto Lomas, Peru, 10 January 2018. The 2018 Dakar says goodbye to the dunes with its fifth and final stage over the Peruvian desert and begins to take height as it enters the Andean mountain range, heading for Bolivia. (Photo by David Fernandez/EPA/EFE)

A reveller takes part in an annual block party known as “Ceu na Terra” (Heaven on Earth), during carnival festivities in Rio de Janeiro, Brazil February 3, 2018. (Photo by Pilar Olivares/Reuters)

Canadian actress Ellen Page and wife Emma Portner arrive at “The Cured” – Los Angeles Special Screening on February 20, 2018 at AMC Dine-In Sunset 5 in West Hollywood, CA. (Photo by Parisa Michelle/Splash News and Pictures)

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)

A man from the Ogiek community harvests honey in Mount Elgon game reserve, where they have reached an agreement with the government allowing them to remain in their ancestral lands in western Kenya, April 26, 2016. (Photo by Katy Migiro/Reuters)