Hi Jane! You should be able to tell the relative size of your babies pretty soon, which will be smaller than the others. Gender in about a month. My guess is that the one lying around will not make it without help.. Could be that there is something wrong with it's legs, and it won't be able to get around to eat and drink. Check out the legs to see if there is anything different about them. Different length, shape, red or swollen joints, etc. will impede it's movement. You will have to decide whether or not you will be able to fix it, and you will need to monitor the chick closely. If there are not any other internal anomolies, just the leg issues, the chick will likely die of starvation unless you help. I've put down several chicks this year with "wonky leg syndrome", but I've had one (bantam Cochin)survive and do very well. Good luck!