When the rot set in: A new compost heap provided salutary lessons for Jane Green

THE GREEN movement never tells you the down side.

I have the West Country's most magnificent compost heap: 10ft square, divided into two bays and embedded in concrete. The cost was astronomical. But memory fades things we would rather not dwell on, and we set about happily filling up one of the enormous bays.

The children were so impressed that the compost heap was included in their visitors' tour of the house and garden, along with the table-tennis room, the bees' nest and the hamster. The elder even once carried the kitchen rubbish bag to the heap, but when he tipped it out, flies swarmed up. He came dashing in to ask, 'Will I catch diseases from the flies?' He was shocked that something environmentally sound should have any disadvantages. By the end of the summer, the heap was enormous.

One morning, I looked everywhere for Teddy, our Irish terrier. I found him wagging his tail and sniffing at the compost heap. As the weekend progressed, I could take him for a walk only if I pulled him away from the heap on his lead. He was in such a state of excitement he was even willing to forgo his meals. We had never seen him so animated. We began to fear the worst. The Irish terrier was bred for ratting and Teddy had found his vocation.

The pest man (or rather, the Environmental Health Officer) told me cheerfully that my compost heap provided ideal winter quarters for the local rat population. They would be warm in the middle and had plenty of rotting food to eat, he assured me, as if my primary concern was the rats. With great delight, he left a dish of poison in a drainpipe and called every week to leave more and report his progress.

'Was it necessary to poison the rats?' I tentatively inquired. He then spoke with great relish of Weil's disease, carried in the rats' urine, which can kill if you become infected. He continued to call weekly, but our greatest barometer of rattiness was Teddy. My husband developed the habit of helping Teddy out by doing a rat patrol on a Saturday morning. Armed with a can of petrol and a box of matches, they would reconnoitre the heap.

One weekend a schoolfriend of my son came to play. His family has the tidiest house and garden I have ever seen. This particular Saturday, the boys were determined to be in on the action. My husband poured petrol down any likely looking holes and set it alight.

I was always too terrified to watch, waiting for that ghastly air-ripping noise of the petrol igniting. Teddy was watching eagerly when out ran a rat, slightly dazed by the smoke. The boys stood at a safe distance, watching as Teddy caught up with the rat and tossed it expertly and viciously into the air. It was dead when it landed, the throw having broken its neck. The dog's instinct served him and us well.

When the boy's mother arrived, her son greeted her with the cry: 'We saw Teddy kill a rat, Mum. He's a very clever dog.' Her expression made all our compost-heap problems worthwhile.

We now have the loveliest compost for the garden, Teddy had had hours of pleasure, my husband thoroughly enjoyed his Saturday morning ritual and the children learnt about recycling and life and death - and all from one compost heap.