Humans aren't the only ones to put on a happy face. These animals also know how to grin, giggle and ham it up with the best of them.
A giraffe gives visitors a distinctive look at the zoo in Duisburg, Germany.
A zoo employee holds a 6-day-old white lion cub at the zoo in Tbilisi. Four white lion cubs were born on Dec. 10, and three survived at Tbilisi Zoo. The white lions, which are only found in the Timbavati nature reserve in South Africa, are not albinos but a genetic rarity, according to the zoo.
Sea lions fight with each other on Pier 39 at Fisherman's Wharf in San Francisco. The sea lions have become a favorite attraction for tourists who visit the area.
A nandu bird appears as happy as can be at Zoo Krefeld in Germany.
A ring-tailed lemur reacts in an enclosure at the Tierpark zoo in Straubing, southern Germany. The animals are native to the arid regions in the southwest of Madagascar.
This emu definitely isn't camera shy. Stephen Schmidt, from the Try It Emu Farm in Marburg, Australia, must be doing something right to generate such a big smile from one of his residents.
This cheeky chameleon looks pleased about having his photo taken at Volcanoes National Park in Rwanda. Along with his happy grin, he ensured he was an eye-catching green and yellow color for the picture.
This meerkat decided to befriend the plush toy version of himself that was accidently dropped into his enclosure by an excited child. From the goofy grin on his face, it looks like this meerkat might have a new pal!
This little piggy went to market, this little piggy stayed at home, and this little piggy smiled for a closeup!
This swan is having a laugh in its winter wonderland in West Berkshire, Britain.
Hope the otter has every reason to be smiling after cheating death. The underweight 8-week-old cub was found wandering alone along the road until she was rescued by a kind-hearted human. She then recovered made some new friends, like this teddy bear.
With it's alien-like smiling face, this baby thornback ray attracted a lot of attention at an aquarium in Hampshire, Britain.
This young fox couldn't conceal its happiness at getting attention.
In this 2008 photo, Dolly was living out her golden years in at the Mistley Place Park Animal Rescue Centre in Essex, Britain. After being rescued from the slaughterhouse, she was allowed to live out the rest of her days in style. Who wouldn't smile at such luck?
Riley celebrates his second birthday at a party thrown by his owner, Maureen Ravelo.
This cheerful mountain goat laughs for a photographer at Mount Evans in Colorado after he and his pals interrupted a photo shoot of the picturesque sunrise.
This grey adult male seal displays a happy grin while lying on the beach.
Cessol the dolphin smiles and blows a welcoming bubble for the camera.
Masha, a female raccoon, shows of her photogenic good looks at the Royev Ruchey zoo in Krasnoyarsk, Siberia.
A 5-year-old gorilla named Yakini rolls around playfully in his enclosure at Australia's Melbourne Zoo.
Bess the boxer would be the envy of every dog in the world with her collection of 180 rugby balls, but sadly her owners keep returning them. She discovers the balls while walking near the Havant Rugby Club in Hampshire, England and their return has saved the club a lot of money. It also earned Bess her own lifetime membership to the club.