This is one boy's amazing picture diary of his pet rodents doing very human tasks. Colin Mclaughlin, from Maryland, USA, has created a hilarious photo collection of his pet guinea pigs, Chester and Sam. (Photo by Colin Mclaughlin/Caters News)

A humanoid dental patient robot, named Hanako Showa, about to be used during a demonstration of dental treatment at Showa University on March 25, 2010 in Tokyo, Japan. The robot was co-developed by the university and tmsuk co. Ltd, and simulates real human patients. The robot has been used for training of procedures in which the dental treatment requires a high level of precision. (Photo by Koichi Kamoshida/Getty Images)

Mortsafes were contraptions designed to protect graves from disturbance. Resurrectionists had supplied the schools of anatomy in Scotland since the early 18th century. This was due to the necessity for medical students to learn anatomy by attending dissections of human subjects, which was frustrated by the very limited allowance of dead bodies – for example the corpses of executed criminals – granted by the government, which controlled the supply.

“They’ve been obsessing me for years. I searched and found them in Benares, on the banks of the river Gange (India). They arrive here to get rid of everything and to wait for death. This existence can last for years, sometimes decades, almost a life. Opposite to mine, well organised and filled as a human life can be, to try in vain to push the limits of its end”. – Denis Rouvre. (Photo by Denis Rouvre)

Nova Scotia Duck Tolling retriever Torrey competes in the 10th annual Petco Unleashed surfing dog contest at Imperial Beach, California August 1, 2015. Proceeds raised at the event go to benefit the San Diego Humane Society. (Photo by Mike Blake/Reuters)

“Ashes and Snow by Canadian artist Gregory Colbert is an installation of photographic artworks, films, and a novel in letters that travels in the Nomadic Museum, a temporary structure built exclusively to house the exhibition. The work explores the shared poetic sensibilities of human beings and animals”. – Wikipedia. (Photo by Gregory Colbert)

“In anatomy, heterochromia refers to a difference in coloration, usually of the iris (but also of hair or skin). Although infrequently seen in humans, complete heterochromia is more frequently observed in other species, where it almost always involves one blue eye”. – Wikipedia (Photo by StooMathiesen)

Wirittorn Narapatarapimol (Belle) a Miss Tiffany Universe contestant tries on earrings in a private dressing room on May 15, 2009 in Pattaya, Thailand. The Miss Tiffany Universe contest has been running for 12 years, with all contestants transexuals or transvestites, aiming to promote human rights for the transgender population in Thailand. In Thailand transexuals are considered a third gender given the Thai name “Katoey”. (Photo Paula Bronstein/Getty Images)