Even very young chicks will "dust bathe" in the shavings in their brooder. This looks like they may be having a seizure; they lay nearly on their sides and kick, sometimes flapping the "up" wing and moving their head in jerky motions. Just think of it as a "pine shavings angel" like a kid trying to make a snow angel. Not a seizure - but a happy chick.
If you have a lot of chicks at one time, you might consider taping a curve of cardboard in the corners of any square or rectangular brooder box you're using, as chicks will pile onto each other in the corners, either to sleep in a pile or because they were frightened/panicked by something and they can smother chicks on the bottom of that pile. (Generally not a problem with 5 or fewer chicks.) Anyway, the curve of cardboard eliminates corners in which chicks can get trapped by the madding crowd.
The introduction of anything new creates fear and suspicion. The first time you put down a dish with some cooked, scrambled egg, or berries, or anything different from their feed, they will act like That's Killer Stuff Which Will Rise Out of the Dish And Eat Us All! Run Away! Run Away!
Only after a brave chick has finally snuck over and pecked at it, will anyone else investigate the Horrible Scary Thing. But after a while, they'll learn to recognize a special plate or dish you use for treats and WANT to gather around as you lower it into the brooder for them.
Try to start them on a nipple waterer right away. It saves SO much mess and bother in the brooder! Regular chick waterers get litter kicked into the water tray, chicks poop in it, they can knock it over, and wet bedding is awful. There's NONE of that with nipple waterers, and the chicks always have clean, fresh water. Healthier and handier - what could be better than that???
Keep a digital camera in the same room as the brooder and keep it charged, with plenty of memory free for a zillion snaps of chicks at play, asleep, or whatever. Take LOTS of photos and just delete the bad shots. You will need to take a lot to get the best ones, otherwise it's sort of frustrating to just use it now and then and never get that great and adorable moment.
