Okay kiddo, have you ever seen a dog that can find things? Well, some dogs are specially trained to use their noses to find things that humans can't smell. These dogs are called detection dogs! They are very good at finding things like drugs, explosives, and even people who are lost.
When a detection dog is trained, a trainer will hide the thing they want the dog to find (let's say it's drugs). The dog will smell around until it finds the drugs, and the trainer will give the dog a treat to reward it. After doing this several times, the dog starts to learn that finding drugs means they get a yummy treat. Then, the trainer will make it harder and harder for the dog to find the drugs, so the dog has to work harder and sniff more carefully.
Once a detection dog is fully trained, they can use their incredible sense of smell to find things that humans would have a hard time finding. This helps keep people safe by detecting things like dangerous chemicals or hidden explosives. Detection dogs are very smart and work hard to keep us all safe.