What Does it Mean?
When someone says a person is “acting like a chicken with its head cut off,” they are telling you that the person is running around in a hurry or a panic.
This is a very common thing to hear said in the Southern US, like in my home state of Texas. It sounds a little gross, but is rooted in the stories of chickens doing exactly that.
A common variation is “running around like a chicken with its head cut off.”
Ways This is Used
There are different ways that this is used in normal speech. Some people mean it to say that someone is running around blind or mindless. Where I live, that is a more rare interpretation but here is how you might hear it:
“Joe was so worried about his wife being in labor, that he was acting like a chicken with its head cut off.” In this example, Joe is nervous and doing that because he doesn’t know how to help or what to do with himself while he is waiting for the new baby.
The more common way I hear this used is when it refers to a person who has a lot of things to do. In that case, you might hear something like this:
“Rose had so many errands to finish, that she was running around like a chicken with its head cut off.” The idea is that she is running around in a hurry trying to get all of her errands done.