wife and I currently have a 2 and half year-old boxer-hound mix that loves to steal and chew. She's gotten slightly better with age, but still will occasionally steal something when our backs are turned, and we find it chewed up an hour or so later. She knows she has done something wrong because she will immediately go to her crate and look at us with sad eyes. We still crate her when we are not home because she can't be trusted to roam the house and we have a half acre fenced in backyard--6 foot privacy fence, but can't leave her in the backyard because she can jump the fence.