wag

[vanilla]

What purpose do tails in animals serve?
Balance?
Emotional indicator?

[Monster104]

Potential non-fatal food source? Something for them to chase when they have nothing else to do?

[Sue Duhnym]

Convenient handle?

[Smeghead]

In dogs, sort of a "sniff here" signpost?

[(^(oo)^)]

To express themselves more clearly?? Probably that's why dogs without their tails look so .... inexpressive.