How to stop other peoples cats coming in my house?

[cybil2403]

Help! I have 3 cats (10 years old)and recently 2 other cats have started coming in my house through the cat flap and helping themselves to food. I've had difficulty catching them, so I set the flap to IN only and gave them a good spraying (soaking)with water in the hope it scares them off, but they continue to come in! One of my cats will not wear a collar so a magnetic cat flap is out of the question. I've tried taking their food upstairs and the others still find it. I don't want to keep my cats indoors, as they will make my life hell!!!!

[meltoadhall]

put the flap to out only or get that cat to wear a collar, dont leave the food down all day?
our 3 have the food down for a while in morning while we get ready but then its lifted when we are out. even its a temporary measure until the other cats realise there is nothing worth coming in for.

[drchasuble]

We used to have a similar problem but it was only solved when we got rid of the cat flap.
Our cat just has to stay out all day.

[gregwithnail]

Cats are quite adaptable. If you set about it sensibly, you can change your cats' eating habits from help-yourself-buffet to dinner-is-served. In other words, train your moggies to come and collect their breakfast and/or dinner at particular times, outside of which there is no food available. Sounds cruel, but cats are hardy and clever. Your cats will catch on pretty quick, even if it means they miss a ouple of meals at the start. Intruding cats will also learn that the only time there's food to be had, YOU are physically there.