# How can I keep other cats from coming in the cat door?
**URL:** https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425
**Category:** In My Humble Opinion
**Created:** [March 20, 2013, 3:42am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425 "2013-03-20T03:42:58Z")
**Posts on this page:** 19
**Page:** 1
### Author:  [@DummyGladHands](https://boards.straightdope.com/u/DummyGladHands)
#### Post date: [March 20, 2013, 3:42am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/1 "2013-03-20T03:42:58Z")
And eating my cats’ food?? Brazen things; they come right in and make themselves at home. Not strays, nor feral cats; these are tagged, well fed kitties.
I can hide just outside the laundry room, where the cat door is, and hit them with the squirt gun, but I can’t be there all the time. Any ideas? Short of locking the cat door?
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### Author:  [@voltaire](https://boards.straightdope.com/u/voltaire)
#### Post date: [March 20, 2013, 3:49am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/2 "2013-03-20T03:49:44Z")
I know they sell cat doors where your cat must wear a collar that sends off a signal that unlocks it. But I dunno if that’s in your budget.
ETA: [Here’s one](http://www.sureflap.com/products/details/1-microchip-cat-door) that actually uses your cat’s existing implanted microchip, if it has one, which makes a collar unnecessary.
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### Author:  [@Nawth\_Chucka](https://boards.straightdope.com/u/Nawth_Chucka)
#### Post date: [March 20, 2013, 4:48am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/3 "2013-03-20T04:48:58Z")
Our friend had a cat door put in that has a magnet release; her cats wear the other magnet attached to a collar. It’s a strong magnet, they’ve been seen dragging cans around on their collar. But the neighbor cats don’t come in her house anymore.
I should point out it cost over $100 to have it be part of her new door.
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### Author:  [@Foggy](https://boards.straightdope.com/u/Foggy)
#### Post date: [March 20, 2013, 5:19am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/4 "2013-03-20T05:19:08Z")
> [@voltaire](#):
>
> eta: [here’s one](http://www.sureflap.com/products/details/1-microchip-cat-door) that actually uses your cat’s existing implanted microchip, if it has one, which makes a collar unnecessary.
> [@](#):
>
> stores up to 32 cats in memory
32! Lol,
😃
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### Author:  [@Disheavel](https://boards.straightdope.com/u/Disheavel)
#### Post date: [March 20, 2013, 5:21am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/5 "2013-03-20T05:21:28Z")
> [@Foggy](#):
>
> 32! Lol, :d
That is exactly what I came back to post.
But I guess I could just add another door next to that one for the other 15 cats to get in.
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### Author:  [@Enkel](https://boards.straightdope.com/u/Enkel)
#### Post date: [March 20, 2013, 7:24am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/6 "2013-03-20T07:24:39Z")
So, I want to know how long it takes the cats to figure out how to let their buddies in. They could become cat overlords with the power to grant access to the human’s abode.
I would love to get one of these doors for my Jack Russell Terrier, but I know she’d user her powers for evil.
I could see her enticing an innocent baby raccoon through the door… saying “oh, sure… we’ll just play a while, then I’ll let you right back out to go find your mama.”
Once the raccoon is inside and she has it trapped, the hunt begins… an hour later, my house looks like a hurricane went through every room in the place.
Unfortunately I know this from more than one game of “get the scared baby raccoon back out of the house.”
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### Author:  [@chappachula](https://boards.straightdope.com/u/chappachula)
#### Post date: [March 20, 2013, 7:30am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/7 "2013-03-20T07:30:27Z")
> [@DummyGladHands](#):
>
> they come right in and make themselves at home… these are tagged, well fed kitties.
So… what’s the problem? You can never have too many kitty-friends. 🙂🙂
But do be a good host, and take their preferences into account.
When they come to visit, attach a note to their collar as the leave, asking the owner to specify which brand of food the cat wants you to have ready for their next visit.
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### Author:  [@the\_O](https://boards.straightdope.com/u/the_O)
#### Post date: [March 20, 2013, 9:16am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/8 "2013-03-20T09:16:57Z")
A dog?
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### Author:  [@Ken001](https://boards.straightdope.com/u/Ken001)
#### Post date: [March 20, 2013, 11:32am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/9 "2013-03-20T11:32:45Z")
We had this problem once. Going away for the weekend we secured the cat door to “IN” only so any cat which popped by for a visit was stuck in the laundry. Sure enough two days later we returned to a distressed visitor which promptly exited through the open door never to be seen again.
I didn’t like doing it but it worked.
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### Author:  [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)
#### Post date: [March 20, 2013, 12:06pm UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/10 "2013-03-20T12:06:01Z")
Solution - have an indoor cat that won’t crap all over the neighbor’s yards and eat songbirds.
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### Author:  [@sandra\_nz](https://boards.straightdope.com/u/sandra_nz)
#### Post date: [March 20, 2013, 12:12pm UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/11 "2013-03-20T12:12:29Z")
Yep, we got one of those cat flaps that reads the existing microchip. It’s worked brilliantly. Not only do the cats no longer get indoors, we don’t even see them outside on our property. It’s like they’ve scratch our property off their list of places to visit!
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### Author:  [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)
#### Post date: [March 20, 2013, 12:19pm UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/12 "2013-03-20T12:19:40Z")
> [@voltaire](#):
>
> I know they sell cat doors where your cat must wear a collar that sends off a signal that unlocks it. But I dunno if that’s in your budget.
My brother had one of these, and it had an interesting design flaw. The collar-activated latch was configured so that it prevented the door from swinging inward unless the collar was present - but it was configured so that the door could swing outward unimpeded, no collar required. Gravity tended to pull the door back to a vertical (closed) position.
So one day while my brother was watching, a raccoon walked up to the outside of the cat door, and started smacking it with a paw. The door bounced outward/open a little bit, then bounced some more, and eventually the raccoon was able to get a paw under it, flip it completely open and crawl into the house. My brother started yelling and waving, and the raccoon did a quick about-face and began running across the yard. Coincidentally, his cat was relaxing in the bushes nearby; startled by all the ruckus, he took off running as well - and promptly collided with the raccoon at high speed. No ill effects in the end, except my brother took a while to stop laughing at the whole fiasco. I don’t know what he’s using for a cat door these days.
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### Author:  [@kferr](https://boards.straightdope.com/u/kferr)
#### Post date: [March 20, 2013, 1:05pm UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/13 "2013-03-20T13:05:30Z")
The magnetic collars can turn a cat to a [life of crime!](http://www.dailymail.co.uk/news/article-2245860/Milo-magnetic-cat-burglar-collared-pilfering-20-sets-keys-neighbours.html)
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### Author:  [@JerrySTL](https://boards.straightdope.com/u/JerrySTL)
#### Post date: [March 20, 2013, 2:46pm UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/14 "2013-03-20T14:46:24Z")
We have a cat and a dog who use the same door. When the cat was younger, she would bring in bunnies, doves, and such. Didn’t kill them so seeing a bunny hopping across the floor or a dove flying in the living room wasn’t unusual. With the dog in the house, other cats don’t try to come in. We did have a neighbor’s dog who would jump the fence and visit.
If you search YouTube there’s a video taken with a night vision camera of a raccoon who comes in through the doggy door; walks right past a dog and cat; eats their food; and then leaves. Both the cat and dog act like it’s no big deal.
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### Author:  [@EmilyG](https://boards.straightdope.com/u/EmilyG)
#### Post date: [March 20, 2013, 3:29pm UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/15 "2013-03-20T15:29:16Z")
OP, if you’re worried about other cats eating your cats’ food, maybe you can only feed your cats at certain times.
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### Author:  [@StGermain](https://boards.straightdope.com/u/StGermain)
#### Post date: [March 20, 2013, 7:59pm UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/16 "2013-03-20T19:59:13Z")
> [@kferr](#):
>
> The magnetic collars can turn a cat to a [life of crime!](http://www.dailymail.co.uk/news/article-2245860/Milo-magnetic-cat-burglar-collared-pilfering-20-sets-keys-neighbours.html)
Weird thing is, did you see all those skeleton keys? British house key must not be like US house keys.
StG
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### Author:  [@DummyGladHands](https://boards.straightdope.com/u/DummyGladHands)
#### Post date: [March 21, 2013, 3:41am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/17 "2013-03-21T03:41:43Z")
Love the microchip cat door, great, no idea that even existed, thanks so much!!
I do feed at specific times, but the gypsies in the palace seem to have figured that out. And the damn things will come all the way into the living room, if I move the dishes!! My little 7lb. guy-well, I pretty much need to free feed him, so this is great, I can totally not thank you guys enough!!
So sick of walking into the kitchen, only to see a cat bottom racing out the laundry room door!!!
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### Author:  [@shijinn](https://boards.straightdope.com/u/shijinn)
#### Post date: [March 21, 2013, 4:01am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/18 "2013-03-21T04:01:43Z")
> [@DummyGladHands](#):
>
> … Not strays, nor feral cats; these are tagged, well fed kitties. …
imho, kitties that you get to play with and not have to be responsible for are a treat. 🙂
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### Author:  [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)
#### Post date: [March 21, 2013, 4:43am UTC](https://boards.straightdope.com/t/how-can-i-keep-other-cats-from-coming-in-the-cat-door/653425/19 "2013-03-21T04:43:33Z")
We wouldn’t have had that problem with our cat Archie–though we didn’t have a cat door. Once he got established in the neighborhood, no other cats showed up on our property! He was the Big Cheese on the street and no other cat (or dog!) was allowed to forget it. 🙂