In this photo taken Tuesday, October 14, 2014, skulls and bones are stacked at the Catacombs in Paris, France. The subterranean tunnels, stretching 2 kilometers (1.24 miles), cradle the bones of some 6 million Parisians from centuries past and once gave refuge to smugglers. The site used to close at 5 p.m., but is now staying open until 8 p.m. The change is mainly aimed at allowing more people to visit and reducing long lines, since it can only hold a limited number of people at a time and visits can't be reserved in advance. (Photo by Francois Mori/AP Photo)

A prototype Rollkers transportation device is displayed during a press event at the Mandalay Bay Convention Center for the 2015 International CES on January 4, 2015 in Las Vegas, Nevada. The product is not a skate; it balances for you and when you place it on the bottom of your shoe, it gives you the ability for faster transportation based on walking. The balance CES, the world's largest annual consumer technology trade show, runs from January 6-9 and is expected to feature 3,600 exhibitors showing off their latest products and services to about 150,000 attendees. (Photo by Ethan Miller/Getty Images)

Villagers gather long grass in the Mekong Delta, Vietnam in the first decade of February 2024. The grasses are used as an alternative for plastic products such as baskets. (Photo by Natnattcha Chaturapitamorn/Solent News)

Katie Handler, veterinary technician with the New England Wildlife Center, reaches to try to capture an oil-covered goose along the Muddy River, Monday, December 9, 2024, in Brookline, Mass., as wildlife rescuers tended to dozens of birds that were soaked in oil after an apparent spill. (Photo by Charles Krupa/AP Photo)

In this Monday, March 16, 2015 photo, Syrian refugee Samira Helal, 17, who is two months pregnant, poses for a portrait at inside her tent at an informal tented settlement near the Syrian border, on the outskirts of Mafraq, Jordan. Nearly 3.8 million Syrians have fled their country and are now registered as refugees, according to the U.N. Most face increasingly desperate circumstances. (Photo by Muhammed Muheisen/AP Photo)

The common brushtail possum (Trichosurus vulpecula, from the Greek for "furry tailed" and the Latin for "little fox", previously in the genus Phalangista) is a nocturnal, semi-arboreal marsupial of the family Phalangeridae, it is native to Australia, and the second largest of the possums.

“They're some of the most intriguing and complex creatures on the planet but they really do have nothing to hide – because theyre totally see-through. Transparent animals – creatures with clear glass-like skin – can be found all over the world but their very existence is still shrouded in mystery. The fascinating organisms verge on the invisible and their translucent skin often helps them elude predators”. – Caters News. Photo: Thornback Skate. (Photo by Ken Lucas/Caters News)

A chevrotain or mouse deer feeds in its enclosure at Zurich Zoo, Zurich, Switzerland, October 17, 2012. (Photo by Patrick B. Kraemer/AP)