The first thing you should know about the story of Amazon product manager Ben Hamm is that he actually named his cat Metric. The next thing you should know is that Metric, like many (all?) cats, has a murderous streak. I am a dog person, yet I still enjoyed Hamm’s short presentation on creating the cat door of his dreams, which locks the door for 15 minutes if it detects Metric attempting to enter the house while carrying prey. For added world balance-benefit, the system automatically sends a “blood money” donation to the National Audubon Society every time Metric’s crimes are detected. Watch the video on Digital Trends.