Tunnel or tail: what a 2025 study walks back about handling mice
Published by Planète Pets · managing editor: Clément Lacaille · how our guides are written
Before the trip in a travel carrier even starts, there is the gesture that takes the rodent out of its cage. That gesture has carried a widely repeated rule for fifteen years: never by the tail. A recent study nuances what looked like a settled matter. Our other guidance on this moment is gathered in the rodent travel and safety section.
Contents · 5 sections
The founding 2010 study
Published by Hurst and West in Nature Methods, the study that changed laboratory practice compared mice picked up by the tail with mice picked up via a tunnel present in their home cage, or simply cupped in open hands (see the study, doi 10.1038/nmeth.1500). The contrast was stark: tunnel-handled mice voluntarily approached the handler, showed little urination or defecation during handling, and displayed low anxiety in the elevated plus maze. Tail-handled mice avoided approach, soiled themselves more, and stayed anxious even after several repeated handling sessions.
That contrast, obtained with an intensive, repeated handling protocol, is the origin of the recommendation now found even in pet-care guides: lift a rodent with a tunnel, a hideout, or two cupped hands, never by the tail.
A 2025 replication that finds almost nothing
A team at Osnabrück University tested the same comparison under different conditions: weekly handling, at the time of cage change, in C57BL/6J and CD-1 mice of both sexes (, Scientific Reports 15:21534, doi 10.1038/s41598-025-07384-w). For plasma corticosterone measured at baseline, after a 15-minute restraint and after a 75-minute recovery period, no significant difference between the two handling methods was found (n = 20 to 27 mice per group). The relative weight of the adrenal glands and thymus, indirect markers of chronic stress, also did not vary by method.
Across the full set of behavioural and physiological measures tracked, only a few differences stood out, with no consistent direction from one measure to the next.
Why the two studies do not conflict
The difference lies in the protocol, not the subject. The 2010 study stacked closely spaced handling sessions, a rhythm close to a daily experimental protocol. The 2025 study reproduced a weekly frequency, closer to what a laboratory mouse experiences between two cage changes — and likely closer, too, to how often a pet rodent is handled a few times a week. The gap between the two methods therefore seems to fade when handling is occasional rather than repeated and closely spaced.
What this changes in practice
Nothing here justifies dropping the tunnel or cupped-hands method: it costs nothing, avoids any risk of tail degloving from a sudden movement, and remains the only studied option that has never shown an unfavourable result. What the 2025 study tempers is the size of the gap claimed for occasional use: if your rodent is only handled a few times a week, consistency and gentleness of the gesture probably matter as much as the exact method. This is a separate question from handling right before a stressful journey, covered in our article on transport stress in rats.
Frequently asked questions
Should the tail still be avoided?
Yes, if only for the mechanical risk of skin degloving, independent of the measured stress level. The tunnel or cupped hands remain the safest gesture, with no identified downside.
Do these studies apply to my hamster or guinea pig?
No, both concern the laboratory mouse. Caution suggests transposing the gesture, not the exact figures: find all our guides on the rodent hub.
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This guide is part of Planète Pets’s Rodents universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.