My kid 3 year old doesn't sit for any activity in school. He just want to run and jump. Initially he was not like this. Few weeks back he suffered from viral infection and after that his behaviour is changed. He has become stubborn, sitting tolerance has decreased, doesn't show any interest in the activities which he used to do earlier like puzzles, homework etc. He used to answer all our questions but now he answers depends on his mood. He has become very moody. How can we improve his behaviour?