Chicken making weird noise !!

[carmen chicks]

Hi, my rhode island red hen is about a year old and is running about with the other hens but she is making this 'growling' noise, its not too loud you have to go near hear to near it, please tell me what it is.

 

[JerseyGiantfolk]

She probably needs to lay an egg or is going broody. Are her feathers all fluffed up and is she sitting on the nest a lot? Those are signs of broodiness. Usually when my hens need to lay, the growl, or scratch around in circles.