Full-time feline photographer Andrew Marttila from Washington, D.C., captured blissful expressions of various cats on catnip, which he used to compile a book, “Cats on Catnip”. The photographer dedicated his time to capturing the euphoric expressions of kitties high on catnip – and the results are absolutely hilarious. (Photo by Andrew Marttila/Caters News Agency)

A robot is seen on Mount Etna, Italy on July 4, 2017. Mount Etna, in Sicily, is a test bed for the approximately three-foot high, four-wheeled machine ahead of a future mission to the moon. It is being conducted by the German Aerospace Centre, the agency which runs Germany's space programme. (Photo by Antonio Parrinello/Reuters)

A tourist poses for a picture with the Sphinx at the Pyramids of Giza in Cairo, Egypt, on October 19, 2011. (Reuters/Jamal Saidi)

“Pivo”, Nissan's concept car is introduced at Nissan's Gallery on September 30, 2005 in Tokyo, Japan. “Pivo” is an electric car in which the direction of the cabin moves 180 degrees, therefore, when making a turn in a different direction, it simply needs to move the cabin without moving the car. (Photo by Koichi Kamoshida/Getty Images)

A costumed guest attends WonderCon Anaheim 2015 at Anaheim Convention Center on April 4, 2015 in Anaheim, California. (Photo by Araya Diaz/WireImage)

In this September 30, 2017 photo, people perform “transvestite target practice” to protest the killings of transvestite prostitutes during the annual LGBQT march in Asuncion, Paraguay. Advocacy groups fear the stigma and attacks against the LGBQT community could get worse now that the country's education minister has banned classes about sexual diversity in schools and even volunteered to help burn all books related to the subject. (Photo by Jorge Saenz/AP Photo)

In this May 4, 2014 photo, a miner holds an amalgam of mercury and gold he mined after working a 28-hour shift at an illegal gold mining process, in La Pampa, in Peru's Madre de Dios region. Thousands of artisanal gold miners sweat through the long shifts and endure, for a few grams of gold, the perils of collapsing earth, limb-crushing machinery and the toxic mercury used to bind gold flecks. (Photo by Rodrigo Abd/AP Photo)

A woman leaves with her television set, as she and others are evicted from their apartment blocks close to the site of last week's building collapse, after their homes were deemed unfit for habitation and marked for demolition, in the Huruma neighborhood of Nairobi, Kenya Friday, May 6, 2016. Following a building collapse which claimed at least 40 lives with more 80 people still unaccounted for, after severe flooding, the government has ordered the demolition of similar unsafe buildings in the area. (Photo by Ben Curtis/AP Photo)