That is why they may become even more interested when someone is stressed, sick, pregnant, or otherwise giving off a different scent than usual.
Even though the behavior is normal for dogs, it can still be redirected with training. Teaching commands, rewarding more polite greetings, and giving dogs other ways to use their noses can help manage these moments. In the end, this habit is not about bad behavior, but about a dog using its strongest natural sense to understand the world around it.