Brush your teeth and get cleaned up for the week ahead! These animals answered the call of good dental hygiene. Here: Hamster holds toothbrush. (Photo by Neo Vision/Getty Images/Amana Images RM)

Wrestler known as Gio Malkriado (top) fights with a fluorescent tube with wrestler Ciclope during an extreme wrestling fight at a temporary wrestling ring inside a car wash in Tulancingo Hidalgo, Mexico October 8, 2016. When the time comes for the so-called Extreme Star Fight, six wrestlers climb into the ring. Once the fighting begins, anything goes. They bash each other with chairs and long neon lights, causing small explosions and scattering tiny pieces of glass everywhere. (Photo by Carlos Jasso/Reuters)

Participants celebrate during the “Chupinazo” (start rocket) to mark the kickoff at noon sharp of the San Fermin Festival, in front of the Town Hall of Pamplona, northern Spain, on July 6, 2018. (Photo by Jaime Reina/AFP Photo)

Rare images of wild tigers in Bhutan, captured by camera traps, show tigers and other animals using high-altitude wildlife corridors which are lifelines to isolated tiger populations and critical to genetic diversity, conservation and growth. Here: A wild Bengal tiger (Panthera tigris tigris) captured on a camera trap in corridor eight at an altitude of 3,540 metres in Trongsa, Bhutan. (Photo by Emmanuel Rondeau/WWF UK/The Guardian)

Underwater photographer of the year – winner. Dancing Octopus by Gabriel Barathieu (France). Location: Island of Mayotte, off the coast of south-east Africa. “Balletic and malevolent”, one judge said of this octopus, hunting in a lagoon. Barathieu waited until spring tides when there was just 30cm of water on the flats and plenty of light in the shallows. (Photo by Gabriel Barathieu/UPY2017)

Christian Balderosdasco, 31, is being pulled up a mud pit after diving for 3 hours to look for gold on March 22, 2017 in Paracale, Philippines. Apart from tunneling and sifting sand, locals dive down murky swamps with the aid of a compressor with air flowing in a small tube for breathing, as they blindly swim under the mud for up to four hours to look for tiny rocks containing gold particles. For decades, local residents at Paracale town work in hazardous conditions scavenging under the earth and diving into tunnels filled with mud using only makeshift tools to mine for gold, often placing their health and lives at risk. (Photo by Jes Aznar/Getty Images)

A man sits waiting for a train on the London Underground in 1890, when the platform floors were still made from wooden floorboards. (Photo by Hi-Story/Alamy Stock Photo)

Elena Chernyshova's vision of Norilsk, Russia, the northernmost city in the world, is a series of surprises by which she extracts otherworldly beauty from ugly realities. Here: 2013. A woman is visible through a narrow passageway between two buildings. Norilsk's urban spaces were designed to shorten distances around large developments and give residents maximum protection from arctic winds. (Photo by Elena Chernyshova)