With more than 40,000 followers on Twitter and 26,400 fans on Vine, it looks like Marutaro the hedgehog from Japan is one of the most popular hedgehogs on the Internet. And as his owner keeps on posting Marutaro’s pictures online daily, Marutaro’s popularity continues to grow. There are hundreds of cute photographs and videos of this little fellow, but the ones with little paper cut-out faces are probably the cutest. As Marutaro lies on his back, his owner gives him a variety of silly expressions and smiles. The 20 best of them will definitely boost your mood!

A greenhouse is a contained quantity of air and light which extends the growing season and enables the thriving of plants otherwise alien to local climate. It creates a bubble of super-nature, where things otherwise impossible become possible. The smell, temperature, humidity and taste of things are significantly different than just outside the thin membrane. It enables us to create different kinds (or quantities) of food, but also to experience different climates and atmospheres. A greenhouse is by definition alien to its site, but creates a significant place in everyday life.

The Atlantic Puffin is definitely a curious-looking bird. The special coloring that this bird develops for the breeding season in the spring is very reminiscent of tropical birds. The bright colors of the beak and the markings around the eyes serve no particular advantage and have evolved as a result of sexual selection. However, Puffins don’t look that pretty all year round. They shed all these festive colors in partial moult after the breeding season is over. They lose the ornaments around their eyes, their face becomes darker, and their beak becomes very different. The natural habitat of these birds is the cold waters of the North Atlantic Ocean.

N.C. Dezendorf, wife of the general manager of the Electro-Motive division of General Motors, christens the new lightweight “Aerotrain” at the company's locomotive works in La Grange, Ill. on August 22, 1955. (Photo by Edward Kitch/AP Photo)

Close Encounter of the Insect Kind: “Check out the awesome face on this praying mantis. I can't get over the mouth, it's like something from a science fiction movie. Of all photographic styles macro is definitely my favorite. I am constantly amazed, in every photo that I take, by the intricate level of detail that exists on even the smallest of creatures. It's a stark reminder that a very complex and infinitely beautiful world exists just beyond our human-sized level of perception. Photo taken in Donnybrook, Queensland, Australia” – Andrew Young. (Photo by Andrew Young/National Geographic Photo Contest via The Atlantic)

A general view shows the Krasnoyarsk hydro-electric power station on the Yenisei River near the Siberian city of Krasnoyarsk, Russia, January 13, 2016. The power plant, owned by EuroSibEnergo company, part of En+ Group, with a generating capacity of 6,000 megawatt (MW), has a ferro-concrete dam 124-metres high and 1065-metres long and is the second largest Russian hydroelectric power station. About 85% of the energy generated is intended for the Rusal Krasnoyarsk aluminium smelter, according to representatives of the power station. (Photo by Ilya Naymushin/Reuters)

A general view of Hong Kong's business district is seen Thursday, August 1, 2013. (Photo by Vincent Yu/AP Photo)

General Maurice Gamelin, General Officer commanding the French Armies, is on a four day visit to England. He went to the staff college at Minley and is seen inspecting an anti-tank gun at Aldershot, on June 7, 1939. (Photo by AP Photo)