Help: new to chickens, is this a roo or a hen?

[jwiggs]

It struts and clucks around, is much more aggressive and rambunctious than the rest of the flock, seems to have a protector's instinct. I fear I have a roo? Any help is much appreciated!

 

[jwiggs]

One more pic, let me know if I should try to take more if that would help determine the sex. Thanks!

 

[fshinggrl]

How old? I think it is a pullet.

 

[Basskids08]

How old? I'm thinking pullet if it's over 16 weeks

 

[pfields]

Looks like a pullet to me.