I'd say its a terrier thing! My staff is 5 and she still rips things up from time to time and of course Mika who is 1 (today

) still does it too at every given opportunity! My fella comes from an old fashioned family where its OK to spank dogs and even children to "teach" them how to behave. I laid down the ground rules very early on in our relationship (before we had kids or dogs) that it was my job to discipline and spanking was out of the question, he respects me and was even a little relieved that it was out of his "hands"! And besides like others have said if this keeps occurring it really is'nt her fault, she is an animal and this kind of behaviour comes naturally to her, we have learned in our house to keep such things out of reach and if we find such a mess then its
me I get angry with for allowing it to happen,
never the dogs!