It comes as no surprise that dogs have a really good sense of smell. What perhaps IS more surprising is just how much better it is than ours.

Back in 2002, scientists from the Sensory Research Institute at Florida State University designed and carried out a study to try to put a dog’s sense of smell into context. For this, they used a substance called n-amyl acetate—an organic compound with a scent similar to apples and bananas. It is commonly found in penicillin, as a paint solvent, or as a flavouring.

The study, documented by Dr James Walker, discovered that a dog can detect such tiny amounts of this substance they are hardly measurable—two parts per trillion, to be precise. That means a dog’s sense of smell can identify chemicals between ten-thousandth and one-hundred-thousandth more diluted than a human is capable of.

So, while a human might be able to tell from a sniff if a cup of coffee has a teaspoonful of sugar added to it, a dog would be able to tell if that teaspoonful of sugar had been added to a million gallons of water.

Or, if you relate this to vision, something a human could see clearly at a third of a mile, a dog would be able to see, just as clearly, at 3000 miles away.

Mind-boggling, isn’t it?

I recall reading, years ago, about cadaver dogs that would indicate for a corpse submerged in nearly a hundred feet of water. Since then, I have heard of drug-detection dogs who can find marijuana in sealed containers immersed in a vehicle fuel tank, or those who smell whale scat from a mile away across a sea inlet. Not to mention all those dogs who sniff out explosives.

More recently, I met two dogs working for my local authority. One of them had been trained to indicate hidden money. When he insisted that a fireplace in one property was a hotspot (pun intended) and it was knocked down, they found £20,000 in cash had been bricked in behind it. The occupants of the house claimed it must be a gift from Santa Claus…

The other dog was trained to help investigate arson by sniffing out when accelerants had been used. A study carried out in 2003 discovered that when tracker dogs meet a human trail at right-angles, they can distinguish the direction in which the person was travelling within five paces. And this is despite all the other scents and smells that have come along since the target passed that way.

All kinds of breeds are used as detection dogs. One of the reasons bloodhounds are favoured a trackers is apparently because those long floppy ears help to waft the odours into its nostrils as it moves, nose downward, along the ground. Dogs can also independently move each nostril, to further help divine the direction of the scent they’re following.

Not only do dogs have approximately 300 million olfactory receptors in their noses, compared to around six million for a human, but the area of their brains devoted to analysing those odours is forty times greater than ours, proportionally speaking.

And even the shape of a dog’s nostrils is designed to aid its sense of smell. The ‘comma’ shape allows a dog to exhale through the side slits, which creates a swirling air pattern that helps sweep more of the scent in via the front of the nose. A study carried out in Norway by the University of Oslo discovered that a hunting dog can sniff in a stream of air for up to forty seconds at the time, which covered about thirty actual breaths.

As if all this wasn’t enough, dogs have a secondary olfactory system that humans don’t possess. The vomeronasal or Jacobson’s organ, which is at the base of a dog’s nasal passage, picks up pheromones, related to sexual readiness. These signals are interpreted by a different area of the dog’s brain, quite separate from the rest of its scenting capabilities.

You may wonder what sparked this post today about the ability of dogs to detect chemicals by scent alone. The answer lies all around us at the moment—the Covid-19 pandemic. With testing apparently in disarray, the scares about asymptomatic carriers and threats of a second wave, could scent dogs provide part of the answer?

It was reported back in July 2020 that a charity in Milton Keynes, UK, called Medical Detection Dogs was training six canines to sniff out the virus. The charity’s co-founder, Dr Claire Guest, has previously trained dogs to detect various forms of cancer, as well as malaria, E.coli, and Parkinson’s disease. With the increasing scepticism towards vaccines, using the biosensors known to man might just provide a worthwhile alternative.

MDD is continuing its trials, part-funded by the UK government and by public donations, in conjunction with the London School of Hygiene & Tropical Medicine and Durham University. It is hoped they might be able to screen up to 250 people an hour at points of entry into the UK and at testing centres.

Fingers crossed…

This week’s Word of the Week is nefelibata, meaning a cloud walker, one who lives in the clouds of their own imaginations or dreams, or one who does not obey the conventions of society, of Spanish and Portuguese origin.

If you’d like to comment on this blog, you can do so over on Murder Is Everywhere.


As we speak, I am in the midst of a Blog Tour for the publication of my new book, the second in the Lakes Crime Thriller trilogy, BONES IN THE RIVER. I should have been talking about the book at Newcastle Noir and CrimeFest as well.

Current circumstances—UK lockdown for Covid-19 coronavirus—have put paid to any physical festivals or conventions. So, everything has moved online, with panels and interviews and readings. I took part in the recent Virtual Noir At The Bar (Episode 5 on April 29, from about 44:00min to 51:00min) instead of actually meeting up, in an actual bar, to do actual readings from our works.

As well as keeping on top of the Blog Tour, I’m also deeply into the planning of the next two books. And that’s where I run into the biggest questions of all.

How are we going to write about the events of 2020 in the future?

If I look at BONES IN THE RIVER, for instance, the events of the story occur at the annual Appleby Horse Fair, held in the Cumbrian market town for hundreds of years and famous as being the largest gathering of Gypsies and Travellers in Europe.

This year it has been cancelled.

The opening scene, in which a man accidentally runs down and kills a child on a deserted country road at night, could still happen in lockdown—but not after he’d just spent an evening having a meal with friends where they were undoubtedly all sitting around a dinner table—inside—in close proximity.

My CSI, Grace McColl, goes from crime scene to office and out into the field again, mixing with both the public and her colleagues. My detective, Nick Weston, goes to interview suspects and potential witnesses in person rather than by phone or Zoom, because how can you really get a feel for the reactions of the people you’re talking to unless you can see them while you talk.

People are brought in for questioning—their legal representatives sitting alongside them. What will happen in future? Zoom again, or will this cause a major leap forwards in projection hologram technology?

Grace visits her mother, Eleanor, who has moved back from the south coast up to Appleby. Grace’s ex-husband, Max, has been making himself useful around Eleanor’s new house and garden, perhaps as a way of trying to reinsert himself into Grace’s life. Even with the slight easing of lockdown due to take place in the UK from June 1, this is dubious behaviour. They have a barbecue—which as it’s outside would probably be allowed. But Nick also attends and he doesn’t count as family. Not sure he and Grace stay the full six feet apart at all times there, either…

Besides, Nick’s a father with a young daughter, Sophie. Would he risk her health by associating with others more than he absolutely had to for his job? And what about Nick’s partner, Lisa, who has been working suspiciously late at a hair and beauty salon that wouldn’t be open for business yet anyway.

While one of the other CSIs is suspended for a supposed error. He’s staying at home in his scruffs, watching the TV and playing video games—perfectly feasible in these lockdown times! But then he gets a visit from one of his colleagues and, instead of insisting the man stays on the doorstep so they can chat (no garden available in a little terraced house in Workington) he invites the man inside his home—without hand sanitiser, gloves or face mask.

The Travelling community at the Fair live in close proximity inside their vardo and bow-top horse-drawn caravans, and spend their time largely out of doors, but at the Fair they all mix and mingle with no thought to cross-contamination. There’s plenty of washing goes on, but it’s mostly of horses in the River Eden, as fits with tradition rather than to prevent the spread of Covid-19 infection.

And at the stand-off near the end of the book, the police are more concerned with the numbers involved than the risks of getting too close to the saliva of others.

If I’d been writing this book next year, and setting it this year, it might have been a very different story altogether.

So, what do I do about the third instalment? Do I mentally set the story pre-winter 2019, when Corona was still just a beer, and a virus was something more likely to be contracted by your computer than by your elderly relatives?

After all, I didn’t specify that BONES IN THE RIVER was set in any particularly year. It’s contemporary but not tied to any specific, non-transferrable event—the millennium, for instance.

But, in a few years’ time, the obvious setting of a book pre- or post-Covid-19 will undoubtedly date it. I went through my very first book recently, KILLER INSTINCT and UN-dated it. I didn’t change the story but I did take out references to minor things that I felt dated it badly. References to computer floppy disks, video cassette tapes—even public phone boxes, most of which have either disappeared from our streets or been turned into tiny libraries or stations for community defibrillators.

The next book I have planned is a bit more of an experiment, and therefore could be set at any time in the last few years. I don’t intend to make reference to Covid-19 in that story. It still feels too soon. Too raw.

This will give me time to see what’s going to change in societal behaviours in the slightly longer term before I start the next Charlie Fox book. If Charlie’s greatest threat to someone in the future is that if they don’t stop what they’re doing, she’ll cough on them, it’s going to change things in a big way…

What are your feelings, both as writers and readers about the inclusion of Covid-19 in books written right now, to be read in the next year or eighteen months? Do you want them to reflect these strange times in full and horrible detail, or do you read as more of an escape of what’s going on around you, and therefore not want to be reminded?

And will pre-2020 become seen as the new Golden Age—both of crime and of life?

This week’s Word of the Week is petrichor, meaning the smell of rain on dry earth. It comes from the Greek petra which means stone and ichor, which means the fluid that flows in the veins of the gods in Greek mythology. My thanks to EvKa for sending me this among a whole list of wonderful words. A gift to treasure for a logophile like me!

You can read and comment on this blog over on Murder Is Everywhere.