One of my chicks is acting different... it has always been the runt of them all and recently it has started to act different. It doesn't seem to forage with the others it likes to stand in the sun and sleep a lot, when I pick it up it doesn't struggle as much as the others (weak?). It's poops are normal and it eats and drinks normal, when the mummas find something yummy it runs over and eats just like the rest of them but it just seems to spend most of it's time sunbathing and sleeping. It's legs are working just fine so it's not Mareks. Does it sound sick and lethargic or just more docile than the rest?