Kids are naturally. Curious its natural
Their brains are like sponges and they can't get info fast enough. They just don't know many of the things that we take for granted.
Somebody once asked world champion, Garry Kasparov, why he and Anatoly Karpov got into so much time trouble in their chess games. He looked astonished at the question and said, "We like to think."
Kids like to learn. Everyrthing is wonderful. Everything is mysterious. So they like to Ask.
Richard Ianelli once defined "four" as "The age a child reaches when you wonder if it had been a mistake teaching him to talk."
Because children are in learning stage, so they learn by asking questions.
Because they seek new knowledge
Children have empty brains when they are born and pretty much need to figure out how the world works. What if you were given instructions filled with words you didn't know? You would have to ask so you could construct it. The best thing is that they have great memories because there are no cobwebs or useless information in their heads yet. Everything in the world relates to something before it or causes something after it so thats a lot of information. Children need to ask more because they also need to build a base.