What Is the Average Life Span of a Moth?

After the pupa stage, moths emerge from their cocoons as adults and the life cycle of the moth begins again. Moth eggs can take anywhere from eight to 110 days to hatch, depending on the environment. Moths are most detrimental to humans when they're in the larvae state. Moth caterpillars eat constantly during this phase until they have enough nutrients to enter into the pupa stage and become adult moths.