If you live in Toronto or anywhere in the GTA, you have probably heard someone say that you can smell bed bugs. Some people describe the scent as sweet. Others say it reminds them of spoiled raspberries or damp towels. A few swear they can smell an infestation the moment they walk into a room.
But what is the truth?
Do bed bugs really smell?
Can the average homeowner rely on scent as a sign of an infestation?
This is one of the most misunderstood parts of bed bug behaviour. So here is a clear explanation based on real science and on what we see every day in homes across Toronto, Vaughan, Mississauga, Brampton, Markham, Scarborough and surrounding areas.
What Bed Bug Odour Is
The smell that people talk about comes from chemicals bed bugs release. These chemicals are called alarm pheromones. Bed bugs release them to communicate when they feel threatened or disturbed.
Heavy infestations can also create another smell which comes from:
- shed skins
- dried blood waste
- crushed bugs
- egg clusters
- large colonies living in tight crevices
The combination creates an odour that some people describe as sweet and rotten at the same time. It is not pleasant. It is not harmless. And it is not always obvious.
Do Bed Bugs Always Smell
No. Most small or early infestations produce zero scent that a human can notice. Professional technicians and exterminators who work with bed bugs daily can sometimes smell an infestation before even finding it. Most homeowners cannot because the scent is subtle until the population is extremely large.
A typical bedroom with ten or twenty bed bugs will not smell like anything. The odour becomes noticeable when there are hundreds or thousands living in furniture, cracks and fabric.
This is why relying on smell alone is very risky.
What Bed Bug Odour Smells Like in Real Life
Here are the descriptions of what people report bed bugs and bed bug infestations smell like:
- a slightly sweet but unpleasant fruity smell
- like a mix of old raspberries and damp cardboard
- a warm and stuffy scent near the bed frame or couch
- a sour smell in tight spaces such as behind headboards
- a faint musty smell similar to worn fabric or old books
The important thing to understand is that the smell is never the same in every home. Heat, humidity, ventilation and how often people sleep in the room all change how strong the scent becomes.
Where in the Infested Room You Might Notice the Odour
Bed bug odour is strongest in places where the bed bugs are densely packed. Common examples in Toronto homes include:
- deep seams of couches
- behind the headboard
- the underside of the box spring
- inside drawer joints
- along baseboards
- around mattress tags
- behind wall hangings or fabric items
Sometimes the scent is strongest only when you disturb the bugs by lifting a mattress or moving a couch cushion. This is because bed bugs release alarm pheromones when they sense they are being exposed (as we talked about in the introduction).
How We Handle Bed Bug Odour in Toronto Homes
When our team encounters a smelly infestation, it usually means the bed bugs have created a dense colony in a tight area. We use an approach that focuses on:
- locating the exact source of the colony
- mechanically removing and crushing egg clusters
- applying professional steam when applicable
- opening crevices and fabric seams to expose hidden groups
- using targeted treatments that bed bugs cannot resist
- monitoring the room after treatment
As the population disappears, the odour fades with it. A clean scent in a treated room is often one of the first signs that the infestation is collapsing.
Bed bug odour is real, but it is not a reliable tool for diagnosing an infestation on its own. Think of it like smoke. It might mean a fire, but it might also be something harmless. The only way to know for sure is to find physical signs or bring in an expert entomologist.
