If someone gives you a duck you better eat it. No matter where you are! Even if you have to “Eat a Duck at Mass!” Take that duck and devour it. Don't leave one scrap.

いただきます！ (ITADAKIMASU) is just like saying grace, but it can be used lightly like "Let's dig in!" or "Let's eat!" It can also be used to accept a gift. It is polite to always say it before eating.