My son will be 4 in April, and he constantly breathes through his mouth. He is a normal, healthy, active little boy. The only time I notice he truly can not breath through his nose is when he is eating. He has to stop to breath, between chewing, swallowing, and eating again. When he gets head colds ( typically in the winter months), he is able to blow his nose and clear mucus. However, now that I think about it, and from watching him over the past couple of weeks specifically looking for breathing, he does not breath through his nose at all. When I model for him, he tries and has no clue how to do it! Thoughts??