No, ignorant tends to imply a lack of knowledge, which is what most children suffer from, only having been on the planet a short time.
vs.
Children’s brains soak up more knowledge in their first 3 years of life, much more effectively, than most of us do in our adult lives. They learn how to talk, eat, dress, walk, read, do basic math, understanding basic concepts like gravity and physics, how to interact with others - basically they learn how to be human in an incredibly short period of time. When they hurt themselves like in the video, it’s largely because they are testing out the world around them in order to better understand it and function within it.