Dogs have nuanced and sensitive sense of smell - much more sensitive than a human. They are easily trained, reliable, and loyal. Simply put, humans have not been able to build a machine better than a dog for finding drugs and other illicit substances, and dogs seem more than happy to do the job!

A list of the various things dogs have been trained to find can be found at

The research is still ongoing, but dogs may even be able to reliably smell whether or not someone has cancer! Find out more here:

Finally, if you have access to Netflix or other streaming services, I recommend you check out the Mythbusters episode called "Hair of the Dog" ( check here ).

The third act features a bunch of proposed drug masking techniques in an effort to fool drug detection dogs.

So please think twice before bringing any illegal substances to your airport. :-)

Dogs have excellent senses of smell and can identify the chemicals used in drugs, explosives, and other things that the police want to know about but can't detect easily themselves without complicated equipment. Dogs are also bred to be inquisitive and enjoy snooping, and can thus be trained to search for these things.

Dogs' noses are some of the best chemical sensors we have! When I worked at the National Science Foundation, part of my job was reviewing grant proposals for 'explosives and related threats.' I asked why they wanted a biologist doing that, and the head guy told me about the dogs' noses.

Nature is an amazing engineer and an amazing designer. Over the billions of years since life first formed, nature has shaped forms of life like dogs and humans that are incredibly complex. Scientists spend their whole lives trying to understand all of the details that go into living things, and there are still a lot of things that we don't know.

One of those things is to detect substances at airports, or at least, to do it as well as dogs can. When I say "do it well," there are a lot of things to take into account. I think that dogs can probably be trained to smell substances from a larger range than a simple electronic device. Also, think of the cost of getting many detectors into many airports. I would guess that raising a lot of dogs is much easier than manufacturing a lot of expensive electronic devices.