Make the boy a list...and make him kiss the chickens. You know you want to!
Well, 23 adults, integrated into the flock, you're okay. But you'll probably have at least 3 dopey birds getting lost behind the buckets or something. It makes for an insanely long instruction list for the petsitter when you have to tell them this stuff! It'll be fine in a few months, I'm sure.
My 20 year old son worried about his chicken-sitting duties, "Mom? Do I have to kiss each bird goodnight, like you do? And I don't know the right order that they like to sleep in -- what if they are in the wrong spot on the roost? Do I have to move them?"