AIBU to want to prevent random cat coming into our house

[Secretmetalfan]

He have two budgies, they spend quite a bit of time out of the cage, but when they are in the cage we usually have all the doors and back door open (we like the fresh air). Lately, every day when we have the back door open a tabby cat comes in and stalks the budgies. Today I saw something out of the corner of my eye and the bloody cat had its nose pressed up against the bars of the cage. How can I keep this cat out the house (obviously without closing the back door) or WIBU to keep my sons water pistol to hand?

Hiss / shout at it. Spray it with water.

You are not unreasonable to want to keep someone else's pet out of your home. Yes to using your son's super soaker. It won't hurt the cat but will deter it.

Can you get a screen door/mesh? I have cats, and I just accept that if I leave my back door open then there's a good chance neighbour cats will try to get in to eat their food. I chase them off when I see them, but they're not really very scared of me and apparently my boys must have extra tasty biscuits because the little buggers are always trying it. So most of the time if I'm not sat within direct eyeline of the door I keep it closed and just open all the windows instead.

It's a cat. Birds are cat food. You've left a door open to a fresh gourmet meal for the cat, it's bound to keep coming. Could you get some sort of fly screen door to allow the breeze in but ensure the safety of your budgies? I know, in an ideal world, you shouldn't have to, but cats are cats and very hard to persuade out of hunting, especially when they know where easy prey are. Personally I'd just make sure my pets, the prey, are safe.

supersoaker he will soon learn hes not welcome ,i would also put super sticky double sided tape on the window ledge to deter him climbing through.cats hate walking on sticky things

Yes, double sided sticky tape it has to walk over and a supersoaker for when you catch it in the act. If you're going to be using the soaker outside try loading it with cheapo orange juice - cats hate citrus.

I have a tabby cat who does this to me as well, he wants to come in to my flat and bully my cats and take their place, I am sure he has an owner because he looks brushed, he is an absolute nightmare and throwing water at him doesnt work

Cats don't like to smell of anything other than themselves. Mentholated rubbing cream is great to spread around doorways, etc to et on their fur. They lick it off, gag and don't come back.

Keep spraying it with water and it might get the hint