Blood spots, rusty faecal marks, shed skins, and eggs tucked into mattress seams are the reliable early signs of bed bugs. Because 1 in 5 people never react to bites at all healthywa.wa.gov.auView source healthdirect.gov.auView source , and reactions in people who do react can take up to 9 days to appear , bites alone cannot confirm an infestation.
Check your mattress seams first. If you find physical traces, call a licensed pest controller straight away. Physical evidence on the mattress tells you more than skin reactions ever will betterhealth.vic.gov.auView source health.vic.gov.auView source . Always check the bedding first.
The signs on your bedding confirm an infestation more reliably than bites do
Physical traces on the mattress are the primary detection signal, confirmed by multiple Australian health authorities betterhealth.vic.gov.auView source healthdirect.gov.auView source health.vic.gov.auView source . Four things to look for.
Blood spots on sheets or mattress. Small spots of blood appear where bugs have been crushed or where feeding has happened betterhealth.vic.gov.auView source healthdirect.gov.auView source . Victorian Department of Health calls them "tell-tale spots of blood on the sheets" health.vic.gov.auView source . Strip the bedding. Look at both the sheet surface and the mattress underneath.
Rusty or dark faecal marks. Bed bug excrement leaves rusty or dark spots on mattresses, bedding, or walls betterhealth.vic.gov.auView source . Healthdirect Australia calls it "brown spotting (bed bug faeces) on your mattress" healthdirect.gov.auView source . Victorian Department of Health notes "black or brown spots of dried blood excrement or 'spotting'" health.vic.gov.auView source . These marks smear when wet and will not wipe away cleanly. That helps you tell them from ordinary dirt.
Shed skins near seams. Nymphs moult as they grow, leaving papery cast skins behind healthywa.wa.gov.auView source . Victorian Department of Health notes "moulted skin shells may also be found near" hiding areas health.vic.gov.auView source . Finding them at the mattress seams is a clear sign bugs have been there a while.
Eggs and empty egg cases. Creamy white eggs about 1 mm long can be tucked into mattress seams and folds, according to WA Health healthywa.wa.gov.auView source . Victorian Department of Health also confirms white eggs as one of the signs health.vic.gov.auView source . Small, but visible in good light.
Find any of these and the next step is clear. Call a licensed pest controller.
Bites tell you less than you think (and look different on darker skin)
Most people who wake up with unexplained marks go straight to their skin. Understandable. But two facts from Australian health authorities explain why that instinct can lead you astray.
First: as many as 1 in 5 people do not react to bed bug bites at all healthywa.wa.gov.auView source healthdirect.gov.auView source . If your partner or child shares the bed and has no marks, that does not rule out an infestation. None.
Second: even people who do react may not notice anything for up to 9 days after being bitten, according to WA Health and Healthdirect Australia healthywa.wa.gov.auView source healthdirect.gov.auView source . Victorian Department of Health notes the delay can stretch to 9 to 14 days in some people health.vic.gov.auView source . By the time a bite mark shows, the infestation has had time to grow.
When bites do appear they are typically red and itchy. Healthdirect Australia describes them as "red, itchy spots that are up to 2cm in size" healthdirect.gov.auView source . In people with a stronger reaction, Victorian Department of Health notes wheals can run from 2 cm to 5 cm wide health.vic.gov.auView source . On black or brown skin, the marks may look purple and be harder to spot, according to Healthdirect Australia .
WA Health notes they often appear on the shoulders and arms, sometimes in distinctive lines healthywa.wa.gov.auView source . Victorian Department of Health notes they can show in orderly rows health.vic.gov.auView source . That pattern is different from the random scatter of mosquito bites.
Worried about a skin reaction? See a doctor. This article is general information, not a substitute for medical advice.
Marks on your skin are a signal to check the mattress. Not confirmation. The physical signs on the bedding are what you need.
Where to check: start at the mattress seams, then work outward
Start at the mattress. All four Australian health authorities confirm mattress seams are the primary hiding spot healthywa.wa.gov.auView source betterhealth.vic.gov.auView source healthdirect.gov.auView source health.vic.gov.auView source . Bed bugs go there first.
The mattress seam check. Pull all the bedding off, then run your fingers slowly along every stitched seam and fold, watching for small brown or black spots, papery shed skins, tiny white eggs, or live bugs. Turn the mattress on its side if you can, to check the underside seams too. Better Health Channel confirms that bed bugs primarily hide in mattresses, particularly along the seams betterhealth.vic.gov.auView source .
Bed frame, bedside tables, and nearby furniture. Once you have checked the mattress, move to the bed frame. Healthdirect Australia lists bed frames, bedside tables, picture frames, behind wallpaper, under carpet edges, and behind skirting boards as other hiding spots healthdirect.gov.auView source . Use a torch. Look into every gap and joint.
If the infestation has spread. Victorian Department of Health notes that early infestations concentrate in the seams, beading, and folds of mattresses health.vic.gov.auView source . Established ones spread further: bed heads, skirting boards, and cracks in plaster . Signs across several areas of the room suggest the infestation has been present for some time.
This is a check of surfaces you can see. A licensed pest management technician can carry out a full professional inspection and confirm whether you have an active infestation.
What bed bugs look like (so you know what you are finding)
Knowing what a bed bug looks like helps you confirm what you find during the mattress check.
Adults are flat and oval. WA Health describes them as 4 to 6 mm long and dark reddish-brown healthywa.wa.gov.auView source . Victorian Department of Health describes them as light brown, roughly the size of an apple seed, with the same flat oval body health.vic.gov.auView source . The colour difference comes down to feeding state: an unfed adult is lighter; one that has recently fed becomes engorged and darker. Both descriptions are right for different feeding states.
Nymphs (juveniles) are smaller, from 1 to 5 mm. WA Health notes they are cream-coloured when unfed and turn red to blackish after a blood meal healthywa.wa.gov.auView source .
Eggs are the smallest thing to spot. WA Health describes them as creamy white and about 1 mm long, hatching in around 10 days in warm conditions healthywa.wa.gov.auView source . Victorian Department of Health also confirms white eggs as one of the visual signs health.vic.gov.auView source .
Live bugs in the mattress seams are definitive. The shed skins, faecal spots, and blood spots covered above are often easier to find than the bugs themselves, especially in an early infestation.
Odour is a late sign, not an early one
Bed bugs can smell. But only once they are numerous.
WA Health notes a distinct "bug smell" that only appears when infestations are severe healthywa.wa.gov.auView source . Better Health Channel describes it as "an offensive, sweet, musty odour from their scent glands, which may be detected when infestations are severe" betterhealth.vic.gov.auView source . Victorian Department of Health notes an "offensive sweet sticky odour when bedbugs are numerous" health.vic.gov.auView source .
All three sources say the same thing: the smell only shows up once there are a lot of bugs. If you cannot smell anything, that does not mean the room is clear. A small early infestation produces no odour at all.
Rely on the physical signs on the mattress. Not smell.
How bed bugs get in: travel and second-hand furniture are the main entry points
Finding bed bug signs at home does not mean you have a hygiene problem. Bed bugs hitchhike.
WA Health notes they can walk short distances to adjoining rooms or be carried over much longer distances inside luggage and belongings healthywa.wa.gov.auView source . Staying in hotels, holiday rentals, or hostels carries a real risk of bringing them home in your bags. With school holidays and travel season coming up, it is worth checking your mattress and luggage after any stay away.
Second-hand furniture is another common route, especially bedroom pieces. WA Health warns against picking up furniture from kerb-side collections, as it could be infested healthywa.wa.gov.auView source . That includes mattresses, bed frames, and sofas.
If you have recently stayed away or brought in second-hand furniture and then spotted the signs above, mention it to the pest controller. It helps them assess quickly.
Once you see signs, call a licensed pest controller: delay spreads the infestation
The health authorities are unanimous on this. Call a licensed pest management company the moment you find physical signs healthywa.wa.gov.auView source healthdirect.gov.auView source health.vic.gov.auView source . Do not wait.
Healthdirect Australia puts it plainly: "If you think that you have a bed bug infestation, call a licensed pest management company for treatment" healthdirect.gov.auView source . WA Health says the same: contact a licensed pest management technician for treatment healthywa.wa.gov.auView source .
Waiting makes it harder. WA Health warns that delay "may cause the infestation to spread, making control more difficult and expensive" healthywa.wa.gov.auView source . Bed bugs reproduce quickly and spread into new hiding spots as their numbers grow, so an infestation that starts in your mattress seams can reach the skirting boards and plaster cracks within weeks.
Do not attempt chemical treatment yourself. According to Victorian Department of Health, a licensed pest control operator must only apply pesticides that are currently registered and permitted for use by the Australian Pesticides and Veterinary Medicines Authority (APVMA) health.vic.gov.auView source . Amateur treatment is unlikely to work. It can push bugs deeper into the walls instead.
For a broader look at pest control in Australia, including how professional inspections work and what different pest treatments cover, see our pest control guide. If you want to understand the signs another common structural pest leaves behind, read about signs of termites in your home.
Common questions about early signs of bed bugs
The most reliable first signs are physical traces on the bedding: small blood spots on sheets or the mattress, rusty or dark faecal marks, shed skins near mattress seams, and tiny creamy white eggs. Bites are unreliable as a first sign because 1 in 5 people never react and reactions can take up to 9 days to appear.
Strip the bedding completely. Examine every seam and fold of the mattress with a torch, looking for brown or black spots, papery shed skins, tiny white eggs, or live bugs. Then check the bed frame, bedside tables, and any nearby furniture. Mattress seams are the primary hiding place, confirmed by multiple health authorities.
According to Healthdirect Australia, bed bug bites are red, itchy spots up to 2 cm in size. Victorian Department of Health notes wheals may reach 2 to 5 cm in people with a stronger reaction. On black or brown skin, the marks may look purple and be harder to see. Bites alone do not confirm an infestation: 1 in 5 people show no visible reaction at all.
In the early stages of an infestation, bed bugs concentrate in mattress seams, folds, and beading. As the infestation grows they spread to bed frames, bedside tables, picture frames, behind wallpaper, under carpet edges, and behind skirting boards. A thorough check starts at the mattress and works outward from there.
Yes, but only when the infestation is large. Multiple Australian health authorities describe a sweet, musty odour from bed bug scent glands, and all attach the same qualifier: it is only detectable when the infestation is severe or numerous. Absence of smell does not mean the room is clear. Physical signs on the mattress are a more reliable early indicator.
It varies. WA Health and Healthdirect Australia both say some people may not notice a reaction for up to 9 days after being bitten. Victorian Department of Health notes the delay can extend to 9 to 14 days. That gap means you could have an active infestation well before any skin marks appear. As many as 1 in 5 people never develop a visible reaction at all.
Found signs on your mattress? Get quotes from licensed pest controllers
A licensed pest management technician can confirm the infestation, assess how far it has spread, and quote you on treatment. The sooner you call, the smaller the job.
Sources
This article is general information, not a substitute for advice from a licensed pest management professional.
- healthywa.wa.gov.auView source
- betterhealth.vic.gov.auView source
- healthdirect.gov.auView source
- health.vic.gov.auView source