First, I cannot believe the difference between chicks that are 2, 2 and a half weeks old, and one that is just one week old. I bought four different chicks at a feed store; the fourth breed was so popular there were no older chicks, just the latest 2-day old delivery. And I've grown so attached to all of them, even though I haven't yet given a permanent name to the youngest one. (She's "FuzzButt" right now.) She's the one who has needed me to clean her bottom twice since I bought her last Thursday afternoon. At least it's not every day.... But I check a few times a day, just in case. The other 3 chicks are easily 3 times as large as FuzzButt in just 6 days. They were not quite twice her size the day I bought them all. She gets bowled over by the others in the brooder multiple times a day. But she still rushes in to tuck under them when they're feeding (some of the feed ends up on her back, and they'll nibble off her back as she goes by). They do snuggle with her when they all settle down for naps. Is there really that much a difference in the growth rate between one and two or 3 weeks old?? The other 3 are really feathering out, and she's only got the very tips of her wing nubbins starting to feather. (But those feathers grew a good half inch IN A 24 HOUR PERIOD!) Now, I don't really know if FuzzButt has pasty butt, but her bottom wasn't as clean as the others, and I couldn't tell if it was pasted shut. But I didn't want to take a chance.... she's sleeping a LOT, far less active than the older chicks, and I worry about her.