A while back I decided to convert a forgotten area at the back of my garden into an organic vegetable patch.

It was all going according to plan until, as I began to turn the soil, I uncovered something so horrible, so terrifying that I nearly gave up right then and there. I uncovered a creature that strikes fear into the hearts of most South Africans, a creature synonymous with terror and standing upon your toilet screaming, creature that has been known to send grown men running:

A Parktown Prawn.

While there are many species of king crickets in South Africa the parktown prawn, scientific name: Libanansidas vittatu, has achieved special acclaim among those in northern Johannesburg, whose gardens they commonly inhabit.

Faced with this 'nightmare' I fought the urge to run. As the little cricket, no bigger than my thumb lunged at my head, I fought the urge to hit it with my spade. And as it lunged at my head again the reason I flicked it into the nearby shrub and not the neighbour?s garden was simple. I like spinach.

A single adult Parktown Prawn, can consume up to four snails a night and we all know how snails wreak havoc on spinach.

What is more, the parktown prawn also feeds on snail larvae, dropped fruit and, quite revoltingly, dog droppings.

If I was going to go the organic route and have an all natural garden, I needed to accept it, prawns and all.

What most people, and often most gardeners, miss is that the key to a healthy and successful garden is a healthy ecosystem. If a specific organism is eradicated or targeted in a garden (like the parktown prawn for instance) then other organisms may also be mistakenly eradicated.

A common example is that of aphids and lady birds. Most chemical aphid poisons also kill lady birds, an aphid predator. Since the lady bird life cycle is longer than that of aphids it is likely the aphids will recover faster and be more numerous than before by the time the lady bird population in your garden has recovered.

Usually a gardener will then apply more poison and the pest eradication cycle often continues until one is entirely dependent on the poison for aphid control. If simple repellent plants were instead planted alongside your roses to deter the aphids, then their population could be kept in check by nature's own devices.

And so, when a few days later I found a rain spider on the wall above my bed, I didn?t scream or reach for a can of deadly insect killer. I simply escorted the scary, hairy fellow outside because rain spiders eat Parktown Prawns.