The Power of Smell: How Animals Use Their Noses

Why Smell is Important for Animals

Animals rely on their sense of smell for survival. They use it to:

• Find food
• Mark their territory
• Identify their offspring
• Detect potential mates

Among animals, bloodhounds are famous for their extraordinary sense of smell. Often called "a nose with a dog attached," these dogs have been bred for tracking for over a thousand years.

Bloodhounds: Masters of Scent Tracking

Bloodhounds have been used to:

• Locate missing persons and children
• Track escaped prisoners
• Provide scent evidence in court

They can follow a scent for more than 130 miles (210 km) and detect odors that are up to 300 hours old. Their sense of smell is at least 1,000 times more sensitive than that of humans.

How the Bloodhound’s Nose Works

A bloodhound’s nose contains:

• Olfactory receptors (ORs) – Special proteins that bind to scent molecules
• Hair-like structures (cilia) – Help trap odor molecules in mucus
• Olfactory bulb in the brain – Processes scent signals

The Science Behind Smell

In 1991, scientists Linda Buck and Richard Axel discovered that:

• The human body has over 1,000 genes dedicated to smell
• Each olfactory receptor (OR) detects a specific type of odor
• Their research led to a Nobel Prize in 2004

This discovery helped explain why animals like bloodhounds have such an advanced sense of smell compared to humans.

Bloodhounds, sometimes referred to as “a nose with a dog attached,” live up to their remarkable reputation for indefatigability, tracking individuals over tens of miles.