The Western Hercules Beetle (Dynastes grantii, often mispelled as "granti") is a species of rhinoceros beetle that lives in Arizona and Utah and in Mexico. It appears in August or September, and grows to a size of 50–80 millimeters (2.0–3.1 in). The imagos usually live 2–4 months, and the larvae may spend 2–3 years before they turn into adults. They are nocturnal and often attracted to lights and they are among the biggest beetles found in the U.S. They are also kept as pets in captivity or used in beetle fighting, most commonly in countries in Asia such as Japan where they are sold in pet shops. Their grayish color turns to near black when wet or moist. They feed on tree sap in the wild by making a small wound in the tree, but this behavior is not harmful to the tree.