American Ringtail Cat - how does this tail wag?
Why do cats wag their tail? When my girl cat wants to go out I open the door for her (she is too fat to get through the cat flap!). If its horrible outside she waits and looks. In fact she almost always waits and looks and I try and encourage her to make up her mind by making an encouraging sort of sound.
While she is trying to figure out what to do her tail wags gently from side to side. She walks outside and her tail stops waging. When she has finally got outside and is sitting on the grass all is calm; a perfectly static tail.
Then she might see something or she thinks she has seen something. Her tail starts wagging again. If it is a bird that she instinctively feels that she must hunt her tail will wag more vigorously.
Sometimes you get the situation of cats sleeping with tail flicking.
All are based on the same underlying emotional state and it is not anger. A wagging tail indicates that our cat is uncertain what to do, in a state of mental conflict; shall I or shan't I do so and so?
When the door is open to go out she is unsure because danger lurks out there. When she sees a bird she wants to attack but the cover on a mowed lawn doesn't allow it; I want to go but should I go, I can't go etc -- more conflict.
This tail movement that reflects an emotional state originates in a physical state, the problem of maintaining balance for which the tail is designed to help achieve. The great tree dwelling and climbing cats such as the clouded leopard and margay to name two, have longer tails than average, much longer in fact, and this also applies to the snow leopard as it has to climb and negotiate rock at a 40 degree slope over very dangerous terrain.
The longer tails tell us that it is the tail that helps maintain balance in the same way we use our arms and legs when maintaining our balance. A cat will throw the tail out as a counterbalance. When balance is at a fine point the tail will move from one position to the next maintaining the balance - it is wagging.
This finely balanced point replicates the emotional state when the mind is in conflict trying to decide what to do when the options are finely balanced.