What good does the kicking activity do for the baby?

Answer 1

Babies kick in response to many of the same things that adult humans or animals kick. Some of it is involuntary movements. The rest can be reactions to stimulation, hunger, pain, etc. Experts also believe that the movements "in utero" (in the womb or uterus) help the developing fetus develop muscle strength. Animal babies show more muscle strength in the weeks after being born than human babies show, because animal babies grow much faster than humans.

If a fetus (animal or human) never moved in the uterus, it would not have put its growing muscles to use, so the muscles would be very weak. If a baby animal or human is born with undeveloped or underdeveloped muscle TONE, the baby could die because it needs respiratory muscles in order to breath. Babies with flaccid (no tone) muscles would not be able to scoot toward its mother (ex. kittens and puppies), so that baby would not get fed and would die without food, mother's warmth, and mother's attention. Human babies born with flaccid muscles would have trouble nursing or sucking on a bottle and could have digestive and respiratory problems from lack of muscle tone. As human babies grow, if it had flaccid muscles, it would not be able to hold its head up, roll over, or begin to crawl.

So, in a sense, human and animal fetuses use the time in the uterus to build muscles-- it's like they are in their own little swimming pool and getting exercise!