question about chicks-pictures added

Hi all! I just got my RIR pullets from the local feed store. i had ordered 12 and asked for them to be in the April 1 order and they called me today to tell me my chicks were in!!! AHHH i was not ready. I was out shopping with my mom so she bought me a 2X2X4' metal watering tub like they use in the ranch supply stores when they sell chicks to put all the chicks in. On top of getting the chicks early they sent 6 extras at no charge and they gave them to me.. Now I have 18 RIR pullets running around! They are so cute though. I noticed on some there is almost a black chip monk type stripe on a couple. Is that common? I see 2 or 3 have well define stripes. Could they be roos then?

 

okay first pic is one with out the stripe.


second two pics are the same chick with the stripe.

 

Sorry the pictuers are not the best