Dog lovers insist that dogs are “man's best friend," and this is certainly true when it comes to hunting. For centuries, hunters have relied on dogs for assistance.

For example, "gun dogs" (sometimes called "bird dogs") help hunters by locating prey and retrieving it once it has been shot. Hounds help by tracking or chasing hunted animals.

Would you believe there's one type of hound that can also help stop crime? It's true! Meet the bloodhound.

Bloodhounds have a very, very good sense of smell. Researchers estimate that their sense of smell is at least 1,000 times stronger than a human's. Police departments around the world have learned to use this special power to their advantage.

Ever wonder what happens when police use a bloodhound to help find a missing person? Let's find out.

When a bloodhound sniffs a scent article, such as a piece of clothing, air rushes through the dog's nasal cavity. The scent of the person creates an “odor image" (a sort of smell photograph) in the dog's brain.

The odor image is created from a variety of smells that a human cannot detect, including sweat, breath and skin. Although the world is full of smells, a bloodhound's sense of smell is so powerful that it can use the odor image to pick out the exact scent trail it needs.

Once the bloodhound finds a scent trail matching the odor image, it can follow that specific smell despite all the other odors in the environment. Bloodhounds have been known to follow a scent trail for more than 130 miles!

If someone has ever walked past you wearing perfume, you've probably noticed that, within a few minutes, the smell disappears. A bloodhound's sense of smell is so strong that it can still smell a trail up to 300 hours old! That would be like someone walking past you wearing perfume and still being able to smell it 13 days later!

The nose isn't the only part of bloodhounds well-suited for tracking. Their signature wrinkly skin helps trap scents, too. Their long, droopy ears also act as scent sweepers, dragging the ground and sweeping scents toward their noses.

For nearly 200 years, bloodhounds have helped law enforcement personnel track missing persons and criminals. Although today's police forces have exciting new technologies available, many believe bloodhounds are still the best option when it comes to tracking.

Wonder What's Next?

Bundle up! The weatherman is calling for snow, sleet and freezing rain in Wonderopolis tomorrow. What does it all mean? Let’s head outdoors to find out!