I've trained my young Boxer, Asterisk, to dingle a bell hanging from the handle of the sliding glass door when she needs to go out. But lately, I've notice that Asterisk was dingling the bell even when she'd just been out. I'd get out of my chair to reprimand her for dingling the bell when she didn't need to go out, but then get sidetracked when I noticed one of my cats wanting in. So I'd open the slider and go back to my computer.
This went on for a couple of weeks before I realized what Asterisk was doing: She dingled the bell to let me know that a cat was on the other side of the slider, wanting in. My desk faces away from the door, so I can't see a cat behind me at the slider. But Asterisk can. And she goes to ring the bell whenever one of the cats wants in.
It's hilarious, really. I never taught her that trick. She figured it out herself. What's more, the cats have learned to ring the bell themselves when they need to go outside, by observing me training Asterisk to ring the bell when
she has to go out. They put two and two together, seeing that every time Asterisk jingled the bell, I'd let her outside. Smart animals! (The above picture is one I took just after Asterisk had jingled the bell to notify me that Christopher wanted in. You can barely see the blue and green cable ties just above her head, from which I've hung two large jingle bells. The buckets on the porch were from the 2 weeks of cold weather when I had to carry buckets of water to the barn for the horses when the water at the barn froze.)