I have 11 wheaten marans chicks, 2 black sumatra chicks, 2 black copper marans and one sumatra game cross that will be 6 weeks old tomorrow. We have not lost any since they hatched, and they have all been very healthy. However, one of the wheaten marans chicks is close to 1/2 or 2/3 the size of the others. This hasn't been a problem up until I tried to wean them off of the heat lamp. All of the other chicks are doing great, and seem to be happier in their new pen. However, in the mornings when I come out, the runt stands by herself looking pitiful. This happened last week and I put them all back under the larger heat lamp. She went back to normal within 30 minutes and was fine all week. However, I tried again yesterday and she was back to pitiful this morning. I put her back under the larger heat lamp (her feet were cold) (this time I only moved her back) and again she was fine almost immediately. She doesn't seem to be as well feathered as the others, but based on the coloring I am pretty sure she is a hen (I have read that roo's feather slower, but there is another one that is definitely a roo and he is fully feathered plus she is smaller than all the others.) In fact, of 11 wheaten marans, it appears based on color and size that there are 10 pullets and 1 rooster. (The 2 black copper also appear to be roosters, but I don't know how to tell on the others.) Has anyone else ever run into this before? Should I just leave her under the heat lamp? I actually put her in with some 2 1/2 wk old chicks so she wouldn't be lonely and they seem to be doing fine. In fact, she is about midway between the 2 1/2 wk olds and the 6 wk olds in size .... How long should it take for her to be able to join the chickens in her age group? Are some chicks just naturally that far behind?