Planes land in fog at Heathrow Airport, west London, as heavy fog covers a many parts of the south east, on April 1, 2014. (Photo by Steve Parsons/PA Wire)

An Armatix employee holds a “smart gun” by the company at the Armatix headquarters in Munich May 14, 2014. The gun is implanted with an electronic chip that allows it to be fired only if the shooter is wearing a watch that communicates with it through a radio signal. If the gun is moved more than 10 inches (25 cm) from the watch, it will not fire. A Maryland gun shop owner has dropped his plan to be the first in the United States to sell the so-called “smart gun” after a backlash that included death threats. (Photo by Michael Dalder/Reuters)

Visitors look at a giant puppet of a grandmother sleeping on a bed inside St George's Hall in Liverpool, northern England July 23, 2014. The grandmother is one of two giant models made for a World War I commemorative event. (Photo by Nigel Roddis/Reuters)

A team of ten acrobats form the shape of a racehorse crossing the winning post ridden by Stefanie Hofer to celebrate the upcoming Dubai Duty Free Shergar Cup at Ascot Racecourse on July 29, 2014 in Ascot, England. The Dubai Duty Free Shergar Cup is the only team-format raceday in the UK and takes place on 9th August. (Photo by Ian Gavan/Getty Images for Ascot Racecourse)

A monkey is led by its trainer Qi Defang during training for a circus in Suzhou, Anhui province, November 29, 2014. Suzhou is known as the hometown of circus troupes in China and has more than 300 circus troupes. (Photo by William Hong/Reuters)

Elaine Vandiver shares a moment with a two-year old alpaca as they touch noses as she washes him at her farm at 1560 Stateline Road Monday, May 11, 2015, in Walla Walla, Wash. (Photo by Michael Lopez/Walla Walla Union-Bulletin via AP Photo)

A model wears a floral head dress as she promotes a chain of garden centres at the Royal Horticultural Soceity's Chelsea Flower Show in London, Britain, May 18, 2015. (Photo by Toby Melville/Reuters)

A giant Santa Claus, created and worn by local artist Ed Terrell, 66, walks home with his son and assistant, Rupanuga, 18, following a ceremony to decorate a scraggly Christmas tree with a single red Bulb in Reading, Pennsylvania, December 7, 2014. A ceremony to decorate the scraggly Christmas tree in Reading, Pennsylvania with a single red bulb, much like Charlie Brown's tree in the animated holiday classic, was postponed to Sunday from Saturday because of rain and cold temperatures, officials said. Officials decided to hold a re-dedication ceremony, which will include a Spanish and English reading from the movie's screenplay, and decorate it with a single red bulb, as in the 1965 animated television special, “A Charlie Brown Christmas”. (Photo by Mark Makela/Reuters)