Why is a dog’s sense of smell better than that of ours?
Dog’s smelling sense
Dog has been faithful friend of man for thousands of years. Most dogs are kept as pets to do useful work like herding sheep or guarding buildings. Dogs see a world that is blurred and has no colour. They are short sighted and see only shades of grey. But dog’s sense of smell is thousands times better than that of ours. If it passes through one place it can identify the same place again due to its acute smelling power. They can sniff illegal drugs and culprits. Custom officers use specially trained dogs for sniffing out illegal drugs.
In our nasal cavity there is a yellowish area of about 250sq. mm. This contains millions of hair like cells which are sensitive to smell. These are called chemoreceptors. They are always wet because of the mucus present there. chemoreceptors are connected to the olfactory bulb in the brain. When smell something its particals along with the air reach the chemoreceptors. There they produce electrical impulses in the nerves. These electrical impulses reach the olfactory bulb and we identify the smell. Studies have revealed that a dogs olfactory bulb is bigger than that of a man that is why the dog have a greater power of smell. Another reason for this characteristic is that the dogs nasal cavity is wetter as compared to that of human beings. This wetness further helps in identifying the smells.