Helen,
Several years back we had what I think of as a once-in-a-lifetime dog, a Rotweiler. Entirely too smart, loyal, all the qualities one could ever hope for in a dog. One of his few undesireable traits though was gluttony. When full grown, but still immature he started rearing up on hind legs to get foodstuffs off of table. A baited mouse trap left on the table one night was two rooms away the next morning, but he never got food from table again. Mouse trap in recliner (with a thin cloth cover so he wouldn't recognize it) stopped the scratching on leather to make a "more comfortable" bed.
Can't even leave a set mouse trap now,,,our runt of a Yorkie would be permanently crippled!
Bob