How to stop my neighbours cat coming in?

[marg7]

My cat is 13 and has a ordinary catflap. My neighbours young 1 year old cat has suddenly starting coming in and pinching my cats food and water. also today the young cat has started to spey my furniture. My cat allows the young cat in. can anyone advice me how to stop this cat cmin in.

[ttfn]

I invested in a super strong water pistol for a similar problem. Worked 100%.

[ubasses]

replace cat flap with one that only opens with collar clip or cats chip if yours has been microchipped

[Barmaid]

i'm with ttfn.

[Fitzer]

The handheld plant misters work as well if they're set to spray a jet, however this only works if you're there at the time, the microchip flaps are very good, ours keeps the squirrels out as well!

[Old_Geezer]

12 bore ?