Elementary school children play outside their classrooms as mount Sinabung volcano spews thick volcanic ash in the background on February 10, 2017 in Karo, Indonesia. Mount Sinabung is one of the most active volcanoes in Indonesia and last erupted in May 2016, killing seven people. (Photo by Albert Damanik/Barcroft Images)

National Geographic photographer Steve Winter has spent most of his adult life shooting wild cats. Photo: A 14-month-old cub, cooling off in a pond, is riveted by a deer that appeared near the shore. Tigers are powerful swimmers; they can easily cross rivers four to five miles wide and have been known to swim distances of up to 18 miles. (Photo by Steve Winter/National Geographic)

Amateur contestants (L-R) Phil Bailey, John Hindle and Eren Emir pose in telephone booths during the annual European Elvis Tribute Artist Contest and Convention in Birmingham, central England January 2, 2015. (Photo by Darren Staples/Reuters)

Photographer and animal lover Chris Keeney shows how to use a PetCam with your own pet and offers expert technical know-how and inspiring creative suggestions to get you started. This is Coulee, a border collie/golden retriver mix from Lethbridge, Alberta, Canada. (Photo by Chris Keeney/Princeton Architectural Press)

Revellers take part in New Year celebrations in Coin, near Malaga, southern Spain, January 1, 2016. (Photo by Jon Nazca/Reuters)

Ron Mueck's “Big Baby” sculpture appears to look round at Jenny Saville's painting “Interfacing” at the Masterpieces Exhibition at Christie's on June 13, 2011 in London, England. The painting and sculpture feature in the exhibition, open to the public from 13th–15th June 2011, which showcases some of the Ј250 million worth of art for sale over the next four weeks. Artists including Michelangelo, Gainsborough, Goya, Stubbs, Monet, Picasso and Renoir are represented. (Photo by Peter Macdiarmid/Getty Images)

Model Bianca Balti prepares backstage at the Iceberg Autumn/Winter 2012/2013 fashion show as part of Milan Womenswear Fashion Week on February 24, 2012 in Milan, Italy. (Photo by Tullio M. Puglia/Getty Images)

Paisley, a standard poodle, is pictured at Intergroom in N.J., March 2014. Intergroom is one of the largest cats and dogs grooming conferences in America. (Photo by Paul Nathan/Rex Features)