bats in the belfry

Bats in the belfry is an older idiom that is used to describe someone who is crazy, unusual, eccentric or simply different than other people. In modern day language it is not a common cliche, but in the past decades it was often used to describe a person who seemed slightly different than everyone else. As with a bat that is in a belfry, this person acts slightly odd or crazy and very eccentric.