It is not considered ethical to keep pet monkeys in many cases. Monkeys are highly intelligent and social animals that have complex needs that are difficult to meet in a home environment. They often require specialized care, large and enriching habitats, and social interactions with their own kind to thrive. Additionally, keeping monkeys as pets can contribute to the illegal wildlife trade and exploitation of these animals. It is important to consider the well-being and welfare of animals before deciding to keep them as pets.