Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, Hungary, June 14, 2016. Millions of these short-lived mayflies engage in a frantic rush to mate and reproduce before they perish in just a few hours during “Tiszaviragzas” or Tisza blooming season from late spring to early summer every year. (Photo by Laszlo Balogh/Reuters)

A reveler and a child street vendor pose for a photo during the Banda de Ipanema Carnival parade in Rio de Janeiro, Brazil, Saturday, January 31, 2015. Rio's over-the-top Carnival is the highlight of the year for many local residents. Hundreds of thousands of merrymakers are beginning to take to the streets in open-air “blocos” parties. (Photo by Silvia Izquierdo/AP Photo)

Visitors look at a tower exhibit of 429 different kinds of pumpkins and squash from all over the world at the Buschmann and Winkelmann pumpkin farm on October 9, 2011 in Beelitz, Germany. The farm, located in Brandenburg state near Berlin, harvests tens of thousands of pumpkins from approximately 40 different kinds between August and October and is known for its elaborate, theme-based pumpkin exhibits. (Photo by Sean Gallup/Getty Images)

A merino lamb attempts to jump out of its enclosure to find its mother shortly before feeding time at the Educational and Reserach Station for Animal Breeding (Lehr- und Versuchsanstalt fuer Tierzucht und Tierhaltung, or LVAT) in Brandenburg state on January 27, 2012 in Gross Kreutz, Germany. Hundreds of lambs have been born at the LVAT in recent weeks in the midst of the station's lambing season. Many of the lambs will be sold just before Easter, when they will have grown to a weight of over 40kg, as lamb is the traditional German Easter meal. (Photo by Sean Gallup/Getty Images)

A Grey Seal pup and it's mother lay in the mud at the Lincolnshire Wildlife Trust's Donna Nook nature reserve on November 24, 2014 in Grimsby, England. Seal pup numbers have increased on last year with over 800 pups born at the reserve so far. Large bull seals are the first to arrive at the reserve in late October or early November where they will wait for females. (Photo by Dan Kitwood/Getty Images)

A Palestinian woman sorts freshly picked dates during harvest season in Khan Younis in the southern Gaza Strip October 4, 2015. (Photo by Ibraheem Abu Mustafa/Reuters)

A tourist stands on the shore of a private beach in Naama Bay, Sharm el-Sheikh, south Sinai, Egypt, Sunday, November 8, 2015. Britain's foreign secretary says airport security in many cities will need to be overhauled if it is confirmed the Russian plane crash in the Sinai was caused by a bomb planted by the Islamic State group or someone inspired by the militants. (Photo by Vinciane Jacquet/AP Photo)

A dressed reveler looks up to the famous cathedral in Cologne, Germany, Wednesday, November 11, 2015. Thousands of carnival supporters celebrate the traditional beginning of the carnival season in Germany. (Photo by Martin Meissner/AP Photo)