Specimens of Molossus molossus are often not identified to the subspecies. It could be quite possible that specimens from Saba, St. Eustatius and St. Martin represent specimens belonging to the subspecies Molossus molossus debilis and specimens from Aruba, Bonaire and Curaçao representing the subspecies Molossus molossus pygmaeus. However, the subspecies on the Dutch Caribbean islands remain unclear.