Anand Varma, a U.S. photographer working for the National Geographic, won the First Prize in the Nature Category, Stories, of the 2015 World Press Photo contest with his series of pictures, which includes this one of spores of a fungus landing on an ant, penetrating its exoskeleton and entering its brain, compelling the host to leave its normal habitat on the forest floor and scale a nearby tree, in this picture taken January 22, 2014 and released by the World Press Photo on February 12, 2015. (Photo by Anand Varma/Reuters/National Geographic/World Press Photo)

On August 18, 2012 the infection spreads again as the undead hordes shamble through Vancouver in search of brains. The annual Zombie Walk has been going on for years and each year gets bigger and bigger. (Photo by Gord Gallagher)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

The Villarrica volcano shows signs of activity, as seen from Pucon, some 800 kilometers south of Santiago, on November 21, 2022. Villarrica volcano is among the most active in South America. (Photo by Mario Quilodran/AFP Photo)

Smoke billows from the Mt Etna volcano as seen from Linguaglossa, Sicily on Monday, August 9, 2021. Europe's most active volcano remains active scattering ashes around a vastly populated area on its slopes. (Photo by Marco Restivo/Barcroft Media via Getty Images)

Revellers take part in a Zombie Walk in Asbury Park, New Jersey October 4, 2014. Thousands of revellers met in Asbury park to attempt to break the Guinness World Record of the largest zombie gathering in the world and raise awareness for brain cancer. (Photo by Eduardo Munoz/Reuters)

A man speaks on his mobile phone on May 31, 2011 in New York City. In a new report by 31 scientists meeting at the World Health Organization's International Agency for Research on Cancer (WHO/IARC) it was found that using a mobile phone may increase your risk for certain kinds of brain cancers. While further scientific work will be conducted, the group of scientists from 14 countries classified cell phones in the carcinogenic category 2B, which is similar to the pesticide DDT and gasoline engine exhaust. (Photo by Spencer Platt/Getty Images)