Your cat sniffs a stranger twice as long as you, and not with the same nostril
Published by Planète Pets · managing editor: Clément Lacaille · how our guides are written
A cat that comes to sniff a visitor's hand then steps back is doing something more precise than it looks. A study published in 2025 by Miyairi, Kimura, Masuda and Uchiyama in PLOS ONE timed that gesture and, above all, recorded which nostril the cat used (see the study, doi 10.1371/journal.pone.0324016). Our other guidance is gathered in the cat care and grooming section.
Contents · 6 sections
The protocol: three odours presented at once
Thirty household cats were tested at home. In front of each animal, a plate held three small tubes three centimetres apart: their owner's odour, an unfamiliar person's odour, and a fresh cotton swab as a control. Samples had been taken from three body areas (behind the ear, the armpit, between the toes) and presented within the hour. Each cat went through three trials five minutes apart, with tube positions randomised.
The stranger holds attention, the rest is less clear-cut
The unfamiliar odour is sniffed markedly longer than the other two: 4.82 ± 0.54 seconds, against 2.40 ± 0.28 s for the owner's and 1.93 ± 0.21 s for the fresh swab. A caution on reading this: the study establishes that the stranger's odour beats both others, but it never tests the gap between the owner's odour and the control. Nothing therefore supports the claim that the cat is more interested in its owner's odour than in a blank swab.
The real finding: a nostril switch
Facing an unfamiliar odour, cats first preferentially engage the right nostril, then shift to the left over subsequent sniffs. This effect is significant only for sniffing duration, not for the number of sniffs. In many vertebrates, the right nostril is associated with processing novel or potentially threatening stimuli and the left with familiar ones — so this switch is consistent with a move from alertness to calm appraisal.
The authors themselves publish a bias worth knowing: the tube placed on the cat's right tended to be sniffed with the left nostril, and vice versa (p < 0.01). Part of the observed lateralisation is therefore geometric rather than cerebral.
What the study does not show
The authors are explicit: their results cannot indicate whether cats recognise specific people from olfactory cues. Media coverage of this study, largely headlined on owner recognition, therefore goes beyond the data. No stress marker was measured either: sniffing longer does not mean being worried. And the protocol covers only human odours, not a new object or a second-hand accessory.
What can reasonably be drawn from it
The most useful move with a cat that does not know you remains leaving a still hand within reach and waiting: the few extra seconds of sniffing observed with a novel odour correspond to appraisal work, and interrupting it amounts to forcing contact. In an already anxious cat, that appraisal time adds to other levers, such as the olfactory cues covered in our article on pheromone diffusers.
Frequently asked questions
Should you hold out a hand or wait for the cat to come?
The study does not compare the two approaches; it only shows that an unfamiliar odour occupies the cat longer, which argues for letting it finish its inspection.
Does a cat recognise its owner's odour?
It is plausible and often asserted, but this study does not demonstrate it: its authors say so in plain terms. Find all our guides on the cat hub.
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This guide is part of Planète Pets’s Cats universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.
