Dogs aren’t just pets, not just animals. They can also be very effective security systems. Even if a dog isn’t specially trained to guard a property, they still know where their home is, who their masters are, and that they need to be protected. This is why, for the most part, dogs are always barking at passer-bys on the road, or why when there’s a thunderstorm they whine (besides a natural fear of loud noises, of course). It is really quite exceptional when you take a moment to think about it.