Do you like dogs, I have had a few different breeds over the years like an Irish Setter and two Beagles.
Beagles are one of my favorite breads! I really think it's amazing how highly attuned we developed their noses to be able to hunt hares.
One of my Beagles was an expert insect hunter. She would dig them out of the dirt!
Yes they're often used by customs agencies around the world in order to detect items being brought in illegally. It's really amazing!
I've heard some dogs used by law enforcment can track scents for many miles even if they are faint.
I'm not sure how far the can track scents I believe they do have to be in the general area. But they are great at finding missing people and even explosives and drugs!
I wonder what explosives smell like to them. Probably better than the people smell haha!
Unfortunatley we can't really ask the dog what it's smelling. But the in the dog's head it's searching for a toy. They train them by hiding the items in their toys. So that's all it's doing.