Licking a frozen aluminum ice cream scraper can cause your tongue to freeze to the metal due to the extremely low temperature of the scraper compared to your saliva. When the tongue makes contact with the cold surface, the moisture from the saliva can freeze almost instantly, creating a bond between the tongue and the scraper. This phenomenon can lead to discomfort and potential injury if the tongue is forcefully pulled away. It is advisable to avoid licking very cold metal objects to prevent such incidents. Understanding the science behind this can help prevent painful experiences.