Three crows knight's hawk, hound and mistress. "Three crows" are also often implicated in the parliament of crows where three crows preside over a larger number of crows and sit in judgment over the fate of another crow. The verdict sometimes results in a crow being set upon by all the other crows. This behavior and their tendency to show up at battlefields and the scenes of murders may be explain the collective term for crows as being a 'murder of crows'. "Three crows" also refers to a tale of three crows (a father, mother and son crow) bothering the king. There
Collective noun have originally been plural in concept, referring to mathematic endeavors, but metonymic shift (the shift in concept from "the endeavors" to "the whole set of endeavors") produced the usage of "mathematics" as a singular entity taking singular verb forms. (A true mass-noun sense of "mathematics" followed naturally.) Nominally singular pronouns can be collective nouns taking plural verbs, according to the same rules that apply to other collective nouns. For example, it is correct usage in both British English and American English usage to say: "None are so fallible as those who are sure they're right." In that case, the plural