Definition & Meaning of "[bite] the hand that [feed] {sb}"

What is the origin of the idiom "bite the hand that feeds someone" and when to use it?

The origin of the idiom "bite the hand that feeds someone" is rooted in the behavior of animals, particularly dogs. Dogs, when fed and cared for by a person, are generally loyal and protective of that person. However, in some cases, a dog might react aggressively or ungratefully, biting the hand of the person who provides for it. This literal scenario, where an animal turns against its benefactor, has been metaphorically extended to human behavior. As an idiomatic expression, this phrase can be used in personal relationships to describe situations where someone betrays or mistreats a friend, family member, or benefactor who has been helping them.