The Plymouth Rock is an American breed of domestic chicken. It was first seen in Massachusetts in the nineteenth century and for much of the early twentieth century was the most widely kept chicken breed in the United States. It is a dual-purpose bird, raised both for its meat and for its brown eggs. It is resistant to cold, easy to manage, and a good sitter.

Broodiness is the action or behavioral tendency to sit on a clutch of eggs to incubate them, often requiring the non-expression of many other behaviors including feeding and drinking. Being broody has been defined as "Being in a state of readiness to brood eggs that is characterized by cessation of laying and by marked changes in behavior and physiology". Broodiness is usually associated with female birds, although males of some bird species become broody and some non-avian animals also show broodiness.