A raised, quivering tail means excitement, or spraying
#0058 Animals & plants
Fact rank
B
No behavioural research (primary); only explanations by vets and animal-behaviour experts (secondary), so B
Wow rank
A
The same posture can mean joy or spraying
Usefulness
B
If it happens facing a wall, suspect spraying
Verification: Supported by evidence
AI verification reports the evidence it found; it does not guarantee that a claim is true.
A cat holding its tail up and quivering it is usually excited, for example happy to see you. But the same posture is also seen when it sprays urine to mark its scent.
Why
The quiver reflects heightened arousal, and spraying is also an aroused, scent-marking behaviour, which is thought to be why the two look alike.Evidence
Secondary Cats Protection (2024). A quivering tail can mean the cat is excited to see you, but it can also happen when a cat is spraying link
Secondary RSPCA. When spraying, the tail is upright and quivering; both male and female cats can spray link
Notes and limits
The draft "in intact males" was removed because the sources say both sexes can spray. There is also "pseudo-spraying" with no urine, which can be a sign of stress. The "why" is not in the sources and is given as a hypothesis.
Derivations
Derived from: 猫が大きくしっぽを振るのは喜びではなくいらだちのことが多い
Derived facts: —