Which medullary index indicates an animal hair?

The medullary index is a measurement used to differentiate between types of hair. In animal hair, the medullary index is typically greater than 0.5, indicating a wider medulla relative to the diameter of the hair shaft. In contrast, human hair usually has a medullary index of less than 0.33. Therefore, a medullary index greater than 0.5 suggests the hair is from an animal.