Common squirrel monkeys observe their Christmas present, a box full of mealworms, at the South America enclosure of the Budapest Zoo, in Budapest, Hungary, 24 December 2017. (Photo by Photo by Attila Kovacs/EPA/EFE/Rex Features/Shutterstock)

Teenage girls are all steamed up these days about straight hair. The steam iron is replacing the huge rollers on which countless teens slept every night to achieve the height and curls fashionable until. The same girls endure having their hair stretched to absolute straightness on the ironing board, and then ironed to keep it that way. Unlike the roller setting, this takes teamwork. Gay Stilley, 14, goes through an ironing session with a couple of her friends at the Stilley Home in Glen Oaks, Queens, New York City on December 23, 1964. With a wary eye, Gay tries to watch the straightening process as one friend stretches her hair with a comb and another does the ironing, in the Stilley kitchen. (Photo by Marty Zimmerman/AP Photo)

In this Wednesday, January 3, 2018 photo, yoga instructor Danuta Wolk-Laniewski, demonstrates goat yoga at the Aussakita Acres farm in Manchester, Conn. The farm is partnering with the Hartford Yard Goats, the Double-A affiliate of the Colorado Rockies baseball team, to offer goat yoga at Dunkin Donuts Park, the team's $71 million stadium in Hartford. (Photo by Pat Eaton-Robb/AP Photo)

Carnival revellers dressed as “Peliqueiros” run along a street in the village of Laza, Spain February 11, 2018. “Peliqueiros”, or ancient tax collectors, pursued villagers through the streets ringing their cowbells and hitting villagers with their sticks. (Photo by Miguel Vidal/Reuters)

Kaye Don seated in the cockpit of his new racing car the “Silver Bullet” at Wolverhampton, England on February 21, 1930, in which he will attempt to beat world land speed record at Daytona. It has two 12-cylinder V shaped engines and each develops 2,000-h.p. The theoretical speed of the car is 275 m.p.h. but the designer estimated that will be able to reach 250 m.p.h. allowing for wind pressures. (Photo by AP Photo/Staff/Puttnam)

Dancers perform during a general rehearsal of “Kreatur” (Creature) by German choreographer Sasha Waltz in collaboration with artist and fashion designer Iris van Herpen and light designer Urs Schoenebaum in Berlin, Germany on June 8, 2017. (Photo by Stefanie Loos/Reuters)

Young children at a Bristol, Great Britain health centre unsure of the benefits of sun-lamps and the special glasses that must be worn, July 1948. The health centre was part of the newly introduced free National Health Service. (Photo by Popperfoto/Getty Images)

An Orchid Mantis (Hymenopus coronatus) is perched on the head of a frog hanging from a tree branch on March 15, 2017 in Padang, Indonesia. (Photo by Riau Images/Barcroft Images)