picture description: Humans are a kind of animal called "mammals."  Female mammals have specialized glands, evolved from sweat glands, that secrete a liquid called "milk."  Newborn and very young mammals drink milk produced by their mothers.  Humans are subject to psychological disorders known as "neuroses."  One common nuerosis is a revulsion at the sight of the human breast.  When a human female cannot reveal her breast, as in a public place, this device, called a "pacifier" is used to provide her baby with oral gratification to substitute for the actual breast.  Adult humans who consume certain substances for recreational use also use this device to combat "bruxism," or grinding of the teeth.