AI Recognizes And Locks Out Murder Cats

Anyone with a cat knows that the little purring ball of fluff in your lap is one tiny step away from turning into a bloodthirsty serial killer. Give kitty half a chance and something small and defenseless is going to meet a slow, painful end. And your little killer is as likely as not to show off its handiwork by bringing home its victim – “Look what I did for you, human! Are you not proud?”

As useful as a murder-cat can be, dragging the bodies home for you to deal with can be – inconvenient. To thwart his adorable serial killer [Metric], Amazon engineer [Ben Hamm] turned to an AI system to lock his prey-laden cat out of the house. [Metric] comes and goes as he pleases through a cat flap, which thanks to a solenoid and an Arduino is now lockable. The decision to block entrance to [Metric] is based on an Amazon AWS DeepLens AI camera, which watches the approach to the cat flap. [Ben] trained three models: one to determine if [Metric] was in the scene, one to determine whether he’s coming or going, and one to see if he’s alone or accompanied by a lifeless friend, in which case he’s locked out for 15 minutes and an automatic donation is made to the Audubon Society – that last bit is pure genius. The video below is a brief but hilarious summary of the project for an audience in Seattle that really seems quite amused by the whole thing.

So your cat isn’t quite the murder fiend that [Metric] is? An RFID-based cat door might suit your needs better.

[via r/Arduino]

56 thoughts on “AI Recognizes And Locks Out Murder Cats

  1. I remember to see a similar setup some years ago (Also I think I read about that setup here in hackaday), but since the image processing software were not very developed at that time, the guy who did that setup thought a clever solution; instead a full color image, he made a clever use of light and shadows, so the images captured were shilouttes of a side view of the cat’s head. So the processing software only had to look for a relatively simple shape (a shape that is altered if the cat holds anything in the mouth).

  2. Birds except starlings I can see as harm, but mice? Donate to the exterminator for every mouse dead. There was another cat flap profiling camera thing here years ago. Denial to live coon, possum, skunk, and a starling.

    1. Mice are the foundation of the ecosystem. House cats are doing incredible damage, not helped by owners consistently thinking their pooch isn’t in on that action.

  3. none of my current cats are effective hunters. i do have a young kitty who is very adept at catching dragonflies but she usually eats them in the yard. one cat is way to fat to be an effective bird slayer, and the other is way to old. in his youth he managed a total of 1 confirmed kills, a small shrew. though he has brought home live prey on many more occasions. several were birds that we just let loose outside, he never did much damage to them.

    1. Too fat? Perhaps not. I once watched a 12 year old, 22 lb. (10 kilo) female cat take a parakeet on the wing at 5 feet in the air. She was an indoor only cat also, so she was unaccustomed to hunting.
      Naturally both the parakeet and its owners (myself and my family) were a little shocked that our fat old cat could do such a thing. (we stopped keeping birds after this incident)
      Cats can and will surprise you.

  4. Why deny your cat their way of showing their gratitude for your generous care? If you don’t overfeed them, they aren’t so inclined to share their meals… If you can’t handle the offerings, don’t get a cat, or keep them indoors. Then again, keeping them indoors, also has disgusting ‘gifts’ to cleanup too, since they don’t always use the box, specially when they feel neglected. I’ve never had a cat, that actually brought anything in the house, always on the porch or doorstep. If they really love you, they leave just the guts…

    1. I used to have a cat that that was free to come and go in and out of the house through a cat flap, during the day. He used to bring home at least one mouse every day, and carefully eat it on mat on the inside of the front door, just under the post hatch in the door. Quite often on returning home from work, I would find mouse guts attached to my mail, while other times, I would have to hunt for a mouse lost in the house. At certain times of the year, he would also take home young rabbits, and once even a squirrel.

      I usually locked the cat flap at night, in order to prevent rude awakenings, but my girlfriend at the time didn’t, so when I was travelling for work, it happen that he would wake her up with a gift. He once presented her at 3am with an alive gift directly on the bed, and announcing himself with a “Hey wake up, looks what I’ve got for you!”. I was told that there was a lot of panic, screaming and swearing involved in that incident.

      I did think of making a similar AI system as described in the article, but never got around to doing it, and now I don’t have that cat anymore, so the need for it has also gone at the same time.

      1. I might’ve traded out the girlfriend and kept cats (nothing in your note says you didn’t do just that, I’m just opining, lol). 😉 I’ve got 4 cats. All are hybrid (indoor / outdoor) cats.
        I can’t understand the “cats shouldn’t hunt” mentality.
        People shouldn’t kill either, but wars & crime happen. Who’s more culpable – a person or a cat?

  5. One of our cats hunts rabbits. He drags them back home over several 6ft high fences, alive, then eats them head first (the head, wtf?) usually sitting in the kitchen.
    When we lock the flap he also smashes it till it breaks and he can get in, so that got expensive quickly.
    I have a killer application for “transparent aluminum”.

    We have a problem with neighbour cats that scent mark our property and a neighbour who wont take responsibility for that – eg lying that they are neutered which they obviously are not.
    So I’m up for cat recognition so I can tell the difference between ours and others and squirt water / pepper / rubber bullets at the invaders to drive them off.

    1. I’ve had two neutered female cats from different litters and parents still scent mark. inside the house, too. had to put pheromone collars on them to stop that behavior.

      One of those two, I swear to god, could jump eight feet straight up and catch a bluejay midair. She was only 7lbs wet, and only slightly bigger in size than the birds she was catching!

    2. Just FYI, male cats may still appear to “spray” even after neutering. Usually this is ‘just’ urine and not the extremely stinky sticky stuff a stag male will spray. The trick seems to be to get them neutered BEFORE they develop the habit of spraying. Your vet can tell you the optimal age. Technically, your neighbor may not be lying. Hint: does the cat still have balls?! No balls and “spraying” = male cat that didn’t get the memo. Balls = not neutered, neighbor lies!!

  6. Am I the only person who sees a problem with allowing your non-native pet out into the neighborhood to hunt at someone else’s birdfeeder? Some of these comments are horrifying.

    1. “ScottL says:
      July 2, 2019 at 5:05 am
      Am I the only person who sees a problem with allowing your non-native pet out into the neighborhood to hunt at someone else’s birdfeeder? Some of these comments are horrifying.”

      Yeah, you are pretty much the only one. You are a non-native to this country as well, your ancestors were/are invasive as well. “Someone” should put their bird feeder where other critters, besides birds, can get at it. If the cats are feeding off the birds, then they are probably also feeding mice, rats, and squirrels too. Probably some bugs too. Had a neighbor like that, he also fed stray cats, pretty much put out food for every living thing wandering by. When the rats started moving over the property line, I had to put out traps, catching 2-3 a night on my porch. Use to chuck the corpses over the fence, since he wouldn’t listen when I tried to explain about his unwanted dinner guests. Took almost 7 months after he moved out, before I stopped catching rats. Rodents reproduce very fast, 2-3 times a year. Never use rat poison, very hard to find the source of the odor, which lasts a couple of weeks…

  7. Cats are a vital element to the improvement of their prey. My Cats catch the slower, older, sicker,and lower IQ .
    Rabbits that munch my garden…DIE. Squirrels that munch my house …DIE. Mice that munch my wiring …DIE

  8. A lot of people think that their cat is bringing them gifts when they find a dead animal in their house, when in reality it is actually the cat taking pity on the human for having such poor hunting skills. And of course they eat the head first. That is where the brain is – all sorts of high calorie fatty tissue up there. Bears in Alaska during the salmon runs do about the same thing – eat the head, peel the carcass, and leave lot of the meat. Why? Because the bears are after the calories for bulking up for winter.

  9. australia has the greatest species extinction rate of any continent. one for the primary causes are domestic and feral cats. all feral cats were once house cats or descendants of them. we’ve lost most of the small marsupial mice and kangaroo rat type species long ago and many bird species are taking a a hammering from pet moggies. rep sociable cat owners have outdoor enclosures and don’t let them run free, especially at night.

  10. At the farm we have free ranging chickens, one sunny day, heard a massive noise, ran outside, the chickens dove for cover under the bushes, the roster was doing battle with a Redtail hawk, who made it off alive, never to return. Supposedly in some states its legal to shoot hawks. Personally, they should all be allowed to work for dinner

  11. Honestly, cats are predators by nature and humans cultivated them not least because they helped to control ‘vermin’ like mice and rats that will quite happily eat and spoil our food stores. As long as they actually eat what they kill, I don’t have a real problem with it. And if they’re feral, well they’re part of the ecosystem too (as are humans, for the record — we’re far worse than even hundreds of “domestic cats”). Don’t feed feral cats unless you’re looking to take it in, leave them to find their own food or starve.

    Personally I think it’s really sketchy and actively /cruel/, given that /we/ created the “problem” as such, to deprive your cat of it’s nature by putting a bell on it or locking it up in an outdoor enclosure where it can’t move about freely and can’t hunt. I realize it’s not a perfect example, but if you wouldn’t do it to a mountain lion/tiger/etc then maybe you shouldn’t do it to your cat. If you want to be “conscientious” in this fashion, just keep your pet inside, period.

    If it bothers you that birdfeeders become bird traps, then don’t use them. After all the whole point of a bird feeders is largely to attract birds so we can enjoy watching them. Except in places where we’ve really screwed up the environment, birds were perfectly capable of feeding themselves before humans came along. You have only yourself and other humans to blame for making birds easy prey by luring them in.

      1. Truthfully I find the claims a bit dubious.

        Human actions seem like a much greater threat given significant habitat loss, pollution, pesticides+poisons to cut down on insect population, and other disruptive effects like excessive lighting and background noise. And that’s before we talk about bird baths/feeders that could lure birds into a seemingly safe spot while putting them in danger of a number of predators.

        I agree that established feral cat populations pose a risk, especially when they’re classed as ‘invasive’, but personally I am not that concerned about people’s pets. Not all cats are particularly interested by birds, either.

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