Capybaras bathe in the hot spring water at the Saitama Children's zoo in Higashi Matsuyama city, Saitama prefecture on December 25, 2013. 13 capybaras in the zoo, originally from South America, enjoyed the hot spring water. (Photo by Toshifumi Kitamura/AFP Photo)

Bonbibi, Treehouse Point, Fall City, WA. The Bonbibi is balanced on two steel yokes. The yokes spread out the load and allow for tree growth and movement in the wind. A small deck hangs from the beams below and uses the treehouse itself to shelter guests. (Photo by Pete Nelson)

Rougine, a 19-year-old female Arab fighter among the Syrian Democratic Forces, made up of US-backed Kurdish and Arab fighters, stands in fatigues embracing another colleague near the village of al-Torshan, 20 km on the outskirts of Raqa on February 6, 2017. (Photo by Delil Souleiman/AFP Photo)

A huge atlas moth, with a wingspan of more than 9in, photographed on an areca nut plantation in Sirsi, India. (Photo by Uday Hegde/Close Up Photographer of the Year)

Local residents crowd a swimming pool during a hot weather in Suining, Sichuan province, 27 July 2008. (Photo by Reuters/Stringer)

A Kenyan Red Cross personnel and a volunteer console a relative of a victim, at the site of a building collapse in Nairobi, Kenya, Saturday, April 30, 2016. A six-story residential building in a low income area of the Kenyan capital collapsed Friday night under heavy rain and flooding, killing at least seven people and injuring over 100 others, Kenyan officials said. (Photo by Sayyid Abdul Azim/AP Photo)

South Korea's Black Eagles aerobatics team performs an aerial display forming a Ying and Yang logo during the Singapore Airshow at Changi exhibition center in Singapore on February 16, 2016. (Photo by Roslan Rahman/AFP Photo)