Why is that baby always sleeping?

It's a baby that's all they can do in the first year

Lol yes dont be fooled by babies speaking coherently in their first year by other manhwas. (￣∇￣")

Babies sleep most of the time by at least before they start to stand up and walk (0month to 9months).. Babies with high energy doesn't stay up for long either, it is more like sudden burst of energy for a couple of hours then they'll sleep again..