I too let my very young chicks (about a week old) outside to scratch in the dirt. I had a tractor with a brooder lamp hanging inside. Everyday the chicks had a ritual of being collected from the brooder, being put into a large rubbermaid tub with pine shavings in the bottom and carried to the tractor. I'd then lay the tub on it's side up near the brooder lamp. This way, the chicks could cruise around the 4' X 8' tractor and get into the box if they needed to get warm and out of the wind and to pile up on each other to take their frequent naps. It only took a couple weeks before most of the chicks would fly right up out of the brooder and into their day tub in eager anticipation of getting to hang out all day in the tractor. I only had 8 birds at the time so it was relatively easy. I would also note that they were under constant supervision when outside. The funny thing was, even after they were some eight months old they'd run straight for the tractor when ever I'd let them out from the coop.
