Punishment or normal behaviour?

[Karen]

She's doing it because she is bored. As a cattle dog, she smart and has energy to spare. She needs a job! Or at least lots of things to do, how much exercise does she get every day? (A tired pup is a well-behaved pup.) How much training has she had?

[Taz_Zoee]

I agree with Karen. Try toys that make her work for treats. A Kong with kibble inside and peanut butter over the end. These things will only last a few minutes, but it will keep her brain busy.
Maybe get her a friend so she's not all alone when you aren't home? I know I shouldn't say that, because dogs are not cheap. But that's part of the reason we got our second dog.

Enroll in an agility class or flyball. Gives her a job and exercise.