9. Pygmy Marmoset
The pygmy marmoset holds the title of the world’s smallest monkey, measuring just 4-6 inches in height and weighing less than 5 ounces. Their tiny size and expressive faces make them undeniably adorable.
However, pygmy marmosets have very specific needs, including a specialized diet, plenty of social interaction, and constant enrichment. They can be challenging to care for and are not legal to keep as pets in all regions.
For fascinating facts and more details, visit National Geographic.