My Kepler Bb humanoids develop cognitive, social, and motor skills faster than humans. Their growth rate though is slower than it is in humans. And they are physically gender neutral until 5 years old(the only way to tell gender before 5 years is via a genetic test).
1 very important motor skill that is absolutely essential for living underground is climbing. The baby room has rocks that go from the crib to the chamber right above it. This helps them climb.
It is kind of like a human child climbing a tree except that with shorter arms, many more rocks are needed.
But yeah, these babies are able to climb at 2 months old(or so I thought). Just to put that in perspective, the year on Kepler Bb is 20 months long and a 2 month old human baby can't do much other than smiling and push ups.
So that means that they would have to be able to get up by themselves practically from birth or at least a few weeks after birth.
A newborn standing in just a few weeks is a bit too much in my opinion.
So I have these major motor milestones so far:
2 months: Climbing
3 months: sitting without support
6 months: standing without support
9 months: walking
1 year: running and jumping
What should I do about this climbing milestone? I still want it before 1 year old(so before 20 months) and I want it as early as it is plausible. But if climbing requires that the baby gets up, than that would require the baby to be able to stand up(and not just as a reflex).
All these other early milestones look like they are at a reasonable point in time, it is just the climbing that looks like it is at an unreasonable point in time. So how early is climbing plausible given that these babies can stand up on their own at 6 months?