2 pullets with tails down

[SweetieChicken234]

Why do 2 of my almost 14 week old pullets keep their tails down? They are either down or like straight but these 2 never have raised their tails!! They are both Delawares and are as sweet as can be. My 3rd Dellie puts her tail up just a bit but not super high either. My Wyandotte pullets have their tails up and so do the cockerels from this flock. Is there a reason why a couple pullets might do this? I tried to get some pics of them with tails either like flat or down. It's odd.

 

[nuthatched]

Feathers could still be growing in and feeling strange