This is Mambo, a mutt chicken that I got in a supposed pullet duo I got a few months ago. At first, I thought it was a pullet, but the feathering is looking very roo-ish to me now. She (he?) is around 6 months old, and if it wasn't for the bahavior, I'd feel confident in saying roo. However, Mambo has, so far, not done any of the usual things associated with young roos: no crowing, no flirting or trying to get frisky with any hens. Also, the wattles and comb don't seem as developed as usual for a roo of 6 months. Is he just a late bloomer? Is there any chance this could just be a really weirdly feathered hen?