Little chicken

[happy_feets12]

Hi guys,
I have one question about one chicken. So he drinks and eats normally, but he is much smaller than the others also than those who later hatched. He likes to rest and sleep a lot, but I'm interested in what you would say about what's going on with him? You can see him in pictures is the brown one, you can't miss him.

 

[sourland]

It may have congenital problems causing it to have failure to thrive. Any possibility that it is a bantam?