Spider Monkeys have a lack of thumbs,making them not good manipulators.They have a prehensile tail that makes up the thumbs. It can use its flexible and strong arms and tail to maneuvering around in the trees. Their toes are used to get a better grip on the branches.They can blend in with other monkeys. That's called Protective Resemblance.
Spider Monkeys have a tendency of living in social groups for protection.They also have very developed taste buds for bad food or not. They social groom to get prey out of the monkeys fur.