This huge male orangutan is having a right old laugh as he squints his eyes and shows his huge teeth. The orangutan, called Bimbo, was relaxing on a platform around 5m high in his enclosure when he broke out into a laugh. But his happy smile soon disappeared when another orangutan came over to see what was going on. Bimbo – the only male in the group of five apes at Leipzig Zoo, in Germany - appears to be laughing in much the same way as a human would. (Photo by Martina Radtke/Solent News)

The 'Cats that Look like Pin-Up Girls' Tumblr features a variety of similarly posed felines. Once the pinnacle of female sexuality, pin-up girls have changed and evolved throughout the years to become the modern day Playboy Bunnies and Sports Illustrated models they are now recognized as.

A male green anole lizard flares his throat fan in a backyard in Cary, North Carolina on April 27, 2021. This pink section is actually a thin flap of skin that hangs down below the green anole's throat. Anoles are renowned for their displays in which they do pushups, bob their heads up and down, and unfurl their colorful dewlaps. The male anole uses it for two primary purposes: to protect his territory and attract a mate. (Photo by Bob Karp/ZUMA Press Wire/Alamy Live News)

Almost two years old male baby orang-utan Dalai looks on in the zoo in Dresden, Germany, 30 March 2017. Dalai was born to mother Daisy in June 2016. (Photo by Filip Singer/EPA)

Eugloss dilemma, male, Florida, Biscayne National Monument. (Photo and caption by Sam Droege/USGS Bee Inventory and Monitoring Lab)

The cast of The Expendables, L-R: actors Jason Statham, Sylvester Stallone, Dolph Lundgren and Terry Crews attended the ringing of the opening bell at the New York Stock Exchange on Wall Street in NYC today. There is something so unsexy (not to mention suspect) about a male who constantly takes off his shirt to flex his muscles while in the company of other alpha males.

The double compound eyes of a male St. Mark's fly (Bibio marci), submitted by Dr. David Maitland from Feltwell, UK. (Dr. David Maitland)

A male deer barks at dawn during the annual deer rutting season at Richmond Park in London, Britain, October 9, 2016. (Photo by Toby Melville/Reuters)