Is getting feathers itchy to chicks?

[Texas Fluffy Feet]

I have a total of 5 chicks who are now 9 days old. They have had the pleasure of being able to spend the past couple of afternoons outdoors since the temps have been near 80 or above. For their 1 week birthday they also graduated to pine shavings in their brooder.
This morning I saw them all engage in a very detailed preening session in their brooder. They were also scratching themselves quite a bit. One chick kept scratching her ears and them making a yawning type motion, like maybe she had itchy ears. They are all eating and drinking and otherwise acting normal. They just seemed itchy. I haven't noticed them doing so much preening before. They are cochins and the do seem to be getting lots of feathers now. Their little wings are really looking like wings and they have foot and tail feathers now too. After a few minutes they all took a nap and then made a quick trip to the food and water areas.
I looked them over under a light, especially the one chick with the itchy ears and I don't see any signs of anything being on them. So I was just wondering if this is all normal behavior and perhaps getting feathers is just an itchy process?

 

[DLS]

Might be growing so fast it is itchy?
How did they like the out of doors?

 

[Texas Fluffy Feet]

They loved it out there! They were to cute pecking and carrying on. I was afraid maybe they had gotten a mite or something outside was why I mentioned them being out. I don't see anything on them though. It was just odd they all preened at once. Maybe that was just another sign of them growing and they are adding their morning grooming to their little daily chicken routine. Or, maybe the preening is kinda like the food and water bowls, once one of them starts something, they all have to do it too.

 

[Drosera]

Oh ya, growing feathers are itchy to the young birds. I've previously raised a house sparrow which I got as a naked nestling, and am currently raising a possibly 2 week old RIR. The sparrow almost looked like he was going mad from the itchies when his feathers grew out. As well, they tend to remove the pins (?) from the feathers, to open them up and be able to preen them properly.

It's bothersome to see, but a perfectly natural stage in their development. They might have all done it at the same time because the first one started, which made all the others think about their itchiness, and it jsut kind of snowballed from there.

Hopefully it will pass quickly for them.