A man walks behind camels at the Birqash Camel Market, ahead of Eid al-Adha or Festival of Sacrifice, on the outskirts of Cairo September 29, 2014. Birqash Camel Market, one of the biggest markets for camel meat in Africa, draws sellers from Libya, Sudan, Somalia and other regions in Egypt. The camels sold at the market are also used in tourism. Traders say that the selling rate for a camel in 2014 is anywhere between 5,000 and 20,000 Egyptian pounds (700 – 2800 USD). (Photo by Amr Abdallah Dalsh/Reuters)

Italian disabled dancer Simona Atzori (top) performs, before a special audience with disabled athletes led by Pope Francis, in Paul VI hall at the Vatican October 4, 2014. (Photo by Tony Gentile/Reuters)

A selection of winning images from the Life in Another Light photo contest 2020, from Kolari Vision. Here: Lights and Shadows in the Dolomites, in the landscape infrared category. (Photo by Tomasz Grzyb/Kolari Vision)

Cave Diver, Anhumas Abyss, Bonito, Brazil: The Anhumas Abyss is an underground cavern with a crystal-clear lake below, more than 260 feet (79 m) deep. A visitor must enter through a narrow opening at the top of the chamber and rappel into the cave. Snorkeling and scuba diving in the lake reveal amazing scenery. Distinctive, conical limestone stalagmites and stalactites occupy the lake and the surrounding area, some reaching 65 feet (20 m) high. (Photo by Marcio Cabral/Nature’s Best Photography Awards 2017)

The secretive indri (Indri indri) of Madagascar, the largest living lemur. It is also critically endangered and highly evolutionarily distinct with no close relatives, which makes its branch one of most precarious on the mammal evolutionary tree. In the likely event that the indri goes extinct, we will lose 19m years of unique evolutionary history from the mammal tree of life. (Photo by Pierre-Yves Babelon/Aarhus University)

An elephant bull charges a female hippopotamus as her calf scampers to safety, in Erindi Private Game Reserve in Windhoek, Namibia. (Photo by Rian van Schalkwyk/Barcroft Media)

Bride to be Lauren Cechak expresses her dislike for a wedding gown after trying it on during Filene's Basement's annual sale July 30, 2010 in Bethesda, Maryland. Hundreds of brides to be and their shopping teams line up early waiting to buy gowns at drastically low prices during the annual sale, dubbed the “Running of the Brides”. (Photo by Mark Wilson/Getty Images)

Who Left The Tap Running by artist Simon McGrath is seen as part of the Sculpture by the Sea outdoor exhibition along the Bondi to Bronte coastal walk on November 4, 2011 in Sydney, Australia. (Photo by Lisa Maree Williams/Getty Images)