Comb and wattle pecking

[BarredRocks3]

I have a flock of 3 barred rock pullets and 3 black sex link pullets that are about 18-19 weeks old. The past 2 weeks their combs and wattle have grown a ton! One of my barred rock pullets has decided to start pulling and pecking my other chickens combs and wattles. The chickens do not seem to like this at all. The same pullet does all the comb and wattle bitting it seems... Is this a normal chicken behavior and if not how may I go about correcting it?

 

[ChickenCanoe]

I don't know your setup but it's normal if they don't have enough space and are bored. Birds with space will spend their time foraging rather than nibbling on each other.
That's why battery hens must have beaks trimmed.