Female cats can produce up to three litters a year. And, one fertile cat female can be the original source for 420 000 kittens in a seven-year period, with her progeny also producing liters.
That is why the work of the Feral Foundation for Wild Cats is so important, say its founders.
The organisation was launched in February 2002 when founding members Jackie Fielden and Warren Baleta decided to tackle the feral and stray-cat problem.
Fielden said: "Both of us have been involved with Friends of the Cat for about eight years, but we decided to focus specifically on stray and feral cats. We work during the night when cats are more active."
They catch between two and 10 cats every night.
Baleta snares the cats in special traps and they are taken to veterinary surgeons who sterilise the animals.
The cats are released in the place where they were caught, enabling them to continue exterminating rats and other pests.
Fielden said: "Now, however, they can no longer breed. A big problem is inbreeding, causing weak and deformed cats to be born. The Feral Foundation aims at eliminating unnecessary pain and suffering and to control numbers."
Fielden says the Feral Foundation operates from her home, but they are looking for premises where cats can be cared for.
"Cats don't stay with us for too long, they constantly come and go. Even so, we do need a little space to care for them. At this stage, money is a huge problem."
For more information about the Feral Foundation for Wild Cats, contact 082 886nbsp;6371.