Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: What's the difference between monkeys and apes? The easiest way to distinguish monkeys from the other primates is to look for a tail. Most monkey species have tails, but no apes or humans do. Monkeys are much more like other mammals than apes and humans are. Answer: tail
A:
What do most species of monkeys have that no apes or humans do?