These adorable twin Capuchin Monkeys are almost guaranteed to make you smile, and could, quite possibly, help you make it through the mid-week blues.

As evidenced by this great series of photos, their tiny, expressive faces also make them excellent practice for any photographer.

The rare twins were born at Zoo Berlin, and excited keepers say they are “developing magnificently”.

Photo Credits: Zoo Berlin

The Capuchin Monkey is considered a “New World monkey” of the subfamily Cebinae. They are readily identified as the "organ-grinder" monkey, and have been used in several movies and television shows.

The native range of Capuchin Monkeys includes Central America and South America, as far south as northern Argentina. In Central America, they prefer to occupy wet lowland forests, notably on the Caribbean coast of Costa Rica and Panama, and deciduous dry forest on the Pacific coast.

Capuchins are known to be black, brown, buff or whitish, but their exact color depends on the species. They generally reach a max length of 30 to 56 cm (12 to 22 in), with tails that are just as long as the body.

Capuchins are diurnal and arboreal. They spend the majority of their day searching for food, with the exception of a midday nap.

They are omnivores and feed on a vast range of food types, including: plant parts (such as leaves, flower and fruit), seeds, pith, woody tissue, sugarcane, bulb, and exudates, as well as arthropods, mollusks, a variety of vertebrates, and even primates.

Capuchin Monkeys often live in large groups of 10 to 35 individuals within the forest, although they can easily adapt to places colonized by humans. Usually, a single male will dominate the group and have primary rights to mate with the females of their group. They are territorial and distinctly mark their territory with urine. Group dynamics are maintained and served through mutual grooming, and communication occurs through various calls.

Females typically produce offspring every two years, following a 160- to 180-day gestation. The newborns cling to their mother's chest and continue to do so until they are larger, when they move to her back. Adult male capuchins rarely take part in caring for the young. Juveniles are considered fully mature within four years for females and eight years for males. In captivity, individuals have been known to reach an age of 45 years, although life expectancy in the wild is only 15 to 25 years.

More adorable pics, below the fold!