Definition & Meaning of "pin back one's ears"

What is the origin of the idiom "pin back one's ears" and when to use it?

The origin of the idiom "pin back one's ears" is not precisely documented, but it likely evolved from the imagery of animals, particularly horses and dogs, which tend to pin their ears back when they are alert, attentive, or reacting to certain stimuli. This ear position can indicate their heightened state of awareness or responsiveness. It is used to encourage someone to pay close attention, be alert, or listen carefully to information, instructions, or a particular situation.