how to prevent pet cats from running away

A cat generally does not want to go where its own scent is not present. For strays, this means that cats park themselves where they are familiar, and will not usually cross into another stray cat's territory. Strays will 'time-share' their communal spaces. This is especially true for neutered cats, which is why sterilisation of strays makes managing their welfare much easier.

For house pets, cats do not usually incline themselves to leave where they have come to consider their territory, i.e. your home. Once a cat has become accustomed to indoor living under your roof, it is unlikely that the cat will want to return to becoming a stray, simply because the cat feels surrounded by its own scent at home, but not beyond the main door.

In order for a cat to feel safe and surrounded by its own scent at home, the cat leaves its scent by stropping (scratching at scratching posts) and rubbing against furniture or on carpets. Any object that is stropped or rubbed by a cat becomes said cat's property.

A cat that has just entered your home will need to surround the home with its scent in order for it to consider your home, its own home. This means providing your cat with cat-furniture to strop on, beds to sleep in, and not removing its scent through over-zealous cleaning. An adult that is neutered may not feel like staying indoors at first, wanting to return to its original stray territory, but eventually when your home smells like its own home, it will much prefer to stay in.

This is not true for un-neutered cats, which is why sterilisation is very important. The urge to find a mate will trump the safety of its own home. Most runaway pets are un-neutered.

While adjusting a pet to indoor living, it may sometimes, even often, get curious as to what lies beyond that main door.

To prevent accidental run-outs by your cat, you can try a few measures.

• If you have a gate, mesh the gate so your cat is unable to dash out through the gate. Otherwise, install a pet gate. 
• Place a spray bottle filled with water at the door, to spray at your cat every time it tries to run out.
• Throw a favourite toy towards the inside of the house when leaving, to distract the cat while you are opening and closing the door to go out. 
• If possible, keep your main doors and windows closed or at least meshed at all times. 

In any case, to make sure your cat is easily identifiable, micro-chip or collar-ID your cat, so that it can be returned to you when found.