A busy rush hour sees thousands of commuters climbing on board a train – as well as holding onto its sides and sitting on the roof before it speeds off. Men, women and children climb and are pulled up onto the roof of the train, which is around 12ft (3.6m) high, as they try to find themselves a space. With no seats available inside, many commuters decide to take the risk and choose a rooftop view for their journey out of Dhaka city, in Bangladesh. (Photo by Yousuf Tushar/Solent News & Photo Agency)

Performers participate in the Day of the Dead parade on Mexico City's main Reforma Avenue, Saturday, October 28, 2017. Mexico's capital is holding its Day of the Dead parade, an idea actually born out of the imagination of a scriptwriter for the James Bond movie “Spectre”. (Photo by Eduardo Verdugo/AP Photo)

Bristol Zoo's baby gorilla Kukena holds onto his mother's arm as he ventures out of his enclosure at Bristol Zoo's Gorilla Island on May 4, 2012 in Bristol, England. The seven-month-old western lowland gorilla is starting to find his feet as he learns to walk having been born at the zoo in September. Kukena joins a family of gorillas at the zoo that are part of an international conservation breeding programme for the western lowland gorilla, which is a critically endangered species. (Photo by Matt Cardy)

Kalei Ferrin,3, holds a sign up in support of gay rights during the San Diego gay pride parade July 16, 2011 in San Diego, California. About 200 active-duty troops and veterans from every branch of the military participated for the first time in the march as the ban on the government policy on homosexuals serving in armed forces, or “Don't ask Don't Tell”, remains in flux in the justice system. (Photo by Sandy Huffaker/Getty Images)

Jane Howorth from national charity the British Hen Welfare Trust holds Liberty the last ex-battery hen to be rehomed on December 29, 2011 in Chulmleigh, England. The rehoming of Liberty signifies the end of the small battery hen cage, which has been phased out and replaced by enriched cages in preparation of the European Union directive banning the smaller cages from January 1, 2012. (Photo by Matt Cardy/Getty Images)

A police poses on the durians during festival durian on the giant mount of durian at northern slopes of Mount Arjuna in East Java. Each year, nine villages in Wonosalam district hold a festival to give thanks for an abundance of this stinky, spiky fruit, which they pile in a 10-meter-high pyramid and distribute among the hungry masses. (Photo by Sigit Pamungkas/JG Photo)

Dressed for the traditional New Year's festival known as “La Diablada”, in Pillaro, Ecuador, Friday, January 5, 2018. Thousands of singing and dancing devils take over the mountain town for six days of revelry in the streets. Local legend holds that anyone who adopts a costume for the celebration and wears it at the event six years in a row will have good luck. (Photo by Dolores Ochoa/AP Photo)

The Syrian refugee folklore troupe Abu Rustom perform at a wedding show at Zaatari refugee camp in the Jordanian city of Mafraq, near the border with Syria February 20, 2017. The Syrian troupe is trying to keep its country's traditions alive by holding traditional dances and performing celebratory sword fights during weddings and other occasions, according to the troupe's leader. (Photo by Muhammad Hamed/Reuters)