Certain simians are a group of primates that includes APES, monkeys, and other related species. They are characterized by their large brains, complex behavior, and long arms. APES are the largest and most intelligent of the simians, and they are found in tropical and subtropical regions of Africa, Asia, and South America. They are highly social animals and live in large family groups. They are also known for their use of tools and their ability to learn sign language.