Strange sounds from my Barred Rock Rooster

[dogdollar]

My rooster makes a very strange sound sometimes when he is out ranging with his girls.......it is a sort of metallic sound, kind of like after you pop open a can of Pringles or tennis balls and you are pulling the metal cap off. Anyone ever heard this before? I think it is his way of giving everyone a warning, but I am not sure........
DD

 

[Katy]

A rooster will call his hens to a special treat when he finds one....I guess it could be described as a popping sound. do they come running when he makes it?