Birds of a feather flock together

Birds of a feather flock together is an English proverb. The meaning is that beings (typically humans) of similar type, interest, personality, character, or other distinctive attribute tend to mutually associate.

The idiom is sometimes spoken or written as an anapodoton, where only the first part ("Birds of a feather") is given and the second part ("...flock together") is implied, as, for example "The whole lot of them are thick as thieves; well, birds of a feather, you know" (this requires the reader or listener to be familiar with the idiom).