Retired Monkeys Step Outside for the First Time After Spending Their Entire Lives in a Lab

Yodel, Diego, Itchy, and Wren are critically endangered cotton-top tamarins. The diminutive little monkeys are native to the rainforests of Northern Colombia, but these four have never seen their beautiful wild home. Yodel and her companions, like thousands before them, were bred deliberately for use in research in the United States.