On GLU I came across a question about the etymology of "*einen Vogel haben*". Literally translated: "to have a bird". You use it when you think that a person's idea, behavior, ... is crazy.

For example, when someone dangerously passes you, you will show him, by tipping your finger on your forehead, that he "*has a bird*". This action is called "*jemandem den Vogel zeigen*", literally "to show someone the bird".

I found the phrase "[bats in the belfry][1]" which has a similar meaning to the German phrase. I've never heard it before and someone else commented that she also hasn't heard it before.

What do you usually say? Do you also have a gesture? And is it offensive?

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I'm interested in both American and British phrases and gesture.

Just as side note: In Germany it is highly controversial if it offensive or not. There were several court decisions pro and contra.


  [1]: http://www.phrases.org.uk/meanings/bats-in-the-belfry.html