THE flock of black Zwartbles in the fields at the top of our garden has settled in well this summer. Once we got used to their inquisitive long faces, with a strip of white down the centre, we considered them an adornment to the landscape. While their white Cheviot companions munch placidly, only occasionally raising their heads, the Zwartbles seem ever alert to what is going on. Nosy, you might say, or intelligent. Or, in light of recent events, contemplating their next diabolical move.

Whenever we cross the field the ringleader will fearlessly approach, like a dog hoping for a biscuit. They’re big beasts, close-up. Like foals, which are two-thirds leg, they are about four feet high, five feet long and two-plus feet at the haunches. If one butted you behind the knees, or simply reversed into you at speed, you’d topple.

Rarely do they act solo. Like sheep the world over, they seem Velcro’d to the tail in front. Where one heads, the others obediently follow. Occasionally I’ve seen one standing apart from the flock, staring towards our garden. When it finds me watching, it holds my eye. It is a little disconcerting. Now, after what happened mid-week, it is somewhat threatening too.

The other afternoon, as Alan was mowing our wilder patch of grass, he noticed one of the Zwartbles on its hind legs, trying to get at a young tree protected by a wooden corral. How odd, he thought, as it jinked around in search of juicy leaves. And how high it can reach.

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Every morning we like to take a quick look at the garden before starting work. One day this week, we heard our neighbours already in theirs, getting a sharper than usual start. Impressive, we thought, although not surprising, since their place is immaculately tended. If the haulage industry ever collapsed, they’d have no fear of starving. Alongside a beautifully laid out garden of flowers, trees, climbers and shrubs, they have the wherewithal to set up a greengrocer’s stall: rhubarb, apples, onions, chard, lettuces, rocket, garlic, beetroot, not to mention what’s growing in the greenhouse. We’re often the beneficiaries of this Garden of Eden.

But it would seem news of its first-class provisions has spread.

While we did our rounds of the flowerbeds, speaking encouragingly to the climbing roses by the trellis, our neighbour appeared, ashen-faced, at our fence. “The sheep have got in,” she said. “Come and see.”

We followed through her gate. What lay before us was a scene of utter devastation, a gardener’s ground zero.

Shortly before, from the kitchen window, her husband had spotted a sheep attacking their clematis. Before he’d even considered his kipper, he raced out to discover they had been invaded not by a single delinquent but the entire flock.

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Seventeen of them were stuffing their faces on their hedges and plants and flowers. After herding them back out into the field – no small feat – he and his wife turned and surveyed the damage.

Terracotta pots were smashed, the door of the greenhouse had been knocked off and lay on the ground, and the step-over apple trees had been gnawed to the knuckle. Gone were their late raspberries and rhubarb, herbs, alpines and succulents. The row of compost bins was overturned, a thick ivy pergola had been eaten to the quick, and a tall hedge was now trimmed as if by a strimmer on amphetamines.

Inside the greenhouse, things were not as bad as they might have been. It seems the animals squeezed their way in, looked around – in the process knocking pots off shelves – and retreated. Not a single tomato had been touched, although an aubergine had been smashed out of its tub. To add to the general disarray, there had been wild toileting on an industrial scale.

“Look at my agapanthus!” our friend cried, spotting it among the shards of its pot. “Look at your husband,” Alan replied. While we had been taking in the extent of the ruination, he had disappeared behind the greenhouse with a long stick. Engulfed in a high hedge, his voice was muffled. A couple of minutes later he gave a shout, and three enormous sheep were flushed from their hiding place. They clattered out, panicking at the sight of us and, unsure in what direction to head, froze. Alan raced to open the gate, I flapped my arms, and they were off, to join their partners in crime. Like a mountain shepherd returned from the slopes, our friend emerged laughing from the hedge.

So how had they got in? The gate had been securely latched. Could they have jumped it? Are Zwartbles world champions in the Fosbury Flop, or do they prefer to pole vault? Did one kneel down and allow the others to use it as a stepping stone?

The answer, it seems, is that heavy and earth-bound though they appear, sheep are equipped with invisible jet packs.

If you are ever bored, Google “can sheep jump?”, and videos of thickly-fleeced sheep clearing fences twice their height will provide hours of amusement. It would seem this flock, possibly enticed by the sight of raspberries, had leapt the gate. Discovering they had landed in an eat-your-own-weight buffet, they began to gorge.

Why now? I expect we will never know. It has been suggested that, with one of their fields mowed short last week for the village cricket match, they were feeling peckish and tempted beyond their usual haunts.

If this were Thought for the Day, I’d use the flock’s wandering to illustrate what happens when people are displaced from their homes and left to fend for themselves in the wilderness. But let’s stick to the Zwartbles. No need to feel sorry for them. They had other acres on which to graze, and yet the allure of a ripe raspberry was probably all it took to turn our friends’ plot upside down.

Nor are they repentant. By afternoon, when the worst of the mess had been cleared, our neighbour looked up. The flock was once more gathered at her fence, staring at her. Earlier I had seen one scrutinising our garden, rather more intently than I liked. Is this when demands for protection money arrive? The Borders has a long history of livestock rustling, which continues to this day. But to have sheep taking the lead is surely new.

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