A ranger of Kenya Wildlife Services (KWS) tries to cover the eyes of 2.5-year-old female Southern white rhino, Elia, to calm down after being shot a tranquilizer from a helicopter during Kenya Wildlife Services (KWS) rhino ear notching exercise for identification at Meru National Park, 350 km from Nairobi, Kenya, on April 5, 2018. (Photo by Yasuyoshi Chiba/AFP Photo)

Residents with faces covered in ash ride on a motorcycle as Mount Sinabung volcano erupts, in Sukandebi village in Karo Regency, Indonesia's North Sumatra province, Indonesia June 13, 2015, in this photo taken by Antara Foto. (Photo by Rony Muharrman/Reuters/Antara Foto)

A bunker at aformer Swiss artillery fortress called Heldsberg stands near the town of St. Margareten, Switzerland March 22, 2015. Heldsberg fortress, located on the Swiss-Austrian border near the River Rhine and Lake Constance was built from 1938 to 1940 and remained in military use until 1992. Since 1993 it is open to the public as Fortress Museum Heldsberg. (Photo by Arnd Wiegmann/Reuters)

Luke Personius, 12, waits for a wave as he surfs before school at sunrise in Hermosa Beach, California April 2, 2015. The group of friends surf at sunrise most mornings, then shower outside and walk to school. (Photo by Lucy Nicholson/Reuters)

A villager carries wood while a blackbuck runs on a field near Bhetnoi village in Ganjam District, in the Indian eastearn state of Odisha on May 20, 2018. Villagers of Ganjam district due to their traditional religious belief consider blackbucks as incarnations of Lord Vishnu and harbingers of rain. (Photo by Asit Kumar/AFP Photo)

A boy listens to a prayer before he and other relatives visit the grave of their loved ones, all minors, who were killed a year ago during the government's war on drugs campaign, at the Tala Cemetery in Caloocan, east of Manila on December 28, 2017, as the world commemorates Holy Innocents' Day. Catholics celebrate the biblical passage when King Herodes the great ordered to kill all newborn babies to kill Jesus Christ. (Photo by Noel Celis/AFP Photo)

In this September 17, 2010 file photo a little brown bat is photographed in La Crosse Wis. Researchers for the first time found that little brown bats appear to be showing resistance to white-nose syndrome, which has killed millions of bats across North America. (Photo by Peter Thomson/La Crosse Tribune via AP Photo)

Lightning strikes during a storm over the Ionian Sea in Calabria, Italy on June 27, 2016. (Photo by Alfonso Di Vincenzo/Pacific Press/Rex Features)