MAKING YOUR GARDEN SAFER FOR YOUR CAT AND DETERRING UNWANTED FELINES
Copyright Harrison Weir
Set up a hose with a sprinkler in the and switch this on whenever you see unwanted cats in the garden. The secret is not to get caught, so don't let the invading cat see you turn it on! If cats continue to enter your home you may have to shut the cat flap and only let your own outside when you can bodyguard him. Otherwise poor frightened your cat may start spraying in the house.
If necessary, block your cat's view out from windows and French windows using Humbol Glass Etch spray. Staring is a method used by cats to intimidate others. Anti-theft devices may be illegal if they hurt burglars or children climbing over your wall or fencing. Your local police station may well have a leaflet which will tell you what is legal. Northamptonshire police produce a useful one itemising what is legal. It is designed to help people stop human intruders but is relevant to feline intruders too.
"Make your own cat some high up sitting places, like a shelf in the branches of a tree, where he can sit and look outward across the garden," says Jon Bowen vet and behaviour counsellor of the Royal Veterinary College. "It is important that these are made facing away from the house, with the view into the house blocked, so that the bully cannot use them to stare in."
If you think the bully is spraying on the wall near your own cat flap, or on the garden door, then clean up thoroughly by scrubbing with biological washing liquid followed by surgical spirit. Plant prickly plants  or sheets of metallic kitchen baking stuff where the cat would stand to spray. Then put some plant pots or garden ornaments further back in the garden so that these get sprayed on rather than the house wall or door, thus keeping the bully's scent marks further away from your cat's core territory in the house.  Make latrines round the edge of the garden - see later FAQ