Hi. We have a baby chick approximately 2 weeks old that is acting strange. We started out with six chicks and we are now down to two. One is acting very strange. She is fine one minute chirping a lot even at night pecking doing chick things then she gets lethargic and doesn’t move. Goes limp and just lays there. The others acted the same way before they died but they died quick and didn’t perk back up the way she has. She does not have pasty butt, she is not cold, or hot, I’ve been giving the chicks corid for four days since that was advised when the third chick died. What is wrong? I’m at a loss.