Dear Old Trainer: My neighbor has a little female Chihuahua, Ratzzy, who has the habit of eating cat poop. She is going to take the dog to the pound if she doesn’t stop. I can’t bear to think of that.

A software engineer spent two years designing a machine learning system to log her cat’s pooping habits, and it involved sensors, an infrared camera, a Raspberry Pi, and about 50,000 pictures of cat ...