Bella, the Escape Artist

When we moved into our current home, I got in the habit of leaving Bella in a pen in the kitchen when I wasn't home. After a couple of months of this, she learned how to escape from the pen. She surprised me by greeting me at the door when I returned from work one day.
The pen is three feet tall. Bella stands about one foot high. I examined the pen and discovered one of it's fasteners had come off near the bottom. I fixed it. Imagine my surprise when she escaped again the very next day. In fact, she was out of the pen in less time than it took me to lock the door and get to the car. The pen was retired.
Outside, she spends time on a tether. Several months with the same tether and she escaped, or so it seemed, again. Turns out this time it was the tether. It broke. So I replaced the tether.
Then, today, I received a knock on the door. My wonderful neighbor was letting me know that Bella was loose. The tether is fine, but Bella was loose. I'm hoping I was simply not careful when I put her on it. Until I have a chance to find out if she escapes again, I'll be taking her out of the leash and she'll be spending more time inside. After all, I can't have her running loose in the neighborhood. She's a little smarter than I want her to be. :)