Do not worry, if they eat and drink just fine. Watch their little butts for pasty butts, too.
If they are all spread out everywhere and not just piled up in a particular area, they probably are OK. If they are piled up, it means, that depending on where they are piled up, they are too warm or too cold, but the first few days they really sleep a lot and it seems that they may not make it, but they do . However, the brooder light gives them warmth and light and they may just be more active at times when you are not watching them.
They will be more active very soon.............