When people are dirty, they take a bath or a shower. Animals don't have soap , but they do keep themselves clean. Many animals with hair, such as dogs and cats, keep themselves clean by licking  their hair. They also use their teeth to pull out small dirty things from their hair. When they lick their hair, it is almost as if they are using a wet brush to clean themselves. Birds take baths to stay clean. First they walk through water that is not deep. Next they beat  their wings to dry themselves. Birds also take sand baths on the ground. It is thought that they do this to drive away parasites . Even fish need cleaning. Fish have very little parasites that live in their mouths. Some fish live by eating these parasites off other fish. Such fish are called "cleaner fish". Larger fish will open their mouths so that the cleaner fish can get in to clean. Some animals that live in groups clean each other, such as monkeys. They often clean one another. One monkey may clean an area that the other monkey can't reach. How interesting it is! The best title of the passage is    _   .
Animals Keeping Clean Different Animals Driving Away Parasites Monkeys Living in Groups