LIGHTNING, it is said, never strikes the same place twice, but this is not entirely true. It can, and does, occasionally hit the same place, although a man called Roy Sullivan of Virginia in the United States survived seven strikes.

On the other hand, flash floods of the kind recently witnessed in the Helmsley-Thirsk area may seem so dramatic, rare and isolated that one might not expect a repetition.

In Yorkshire, however, there are places where flash floods have devastated the same district on more than one occasion. I am not referring to those places which are regularly awash with overflowing river water, such as York, Malton, Stamford Bridge and Boroughbridge, nor am I considering the effect of England's most volatile river, the Swale, which can rise by as much as 10ft in a mere 20 minutes.

I am referring to small places, some without a major river, which seem to attract flash floods and one wonders whether the geographical nature of the ground in such places lends itself to the creation of abnormal weather patterns through some local disturbance of the atmosphere.

Helmsley, on the banks of the River Rye, is a recent example of a small community suffering a repeat disaster. The floods of June 19-20 were devastating in their speed and ferocity, and the full damage is yet to be assessed. Similarly, the havoc at nearby Sutton under Whitestonecliffe, Thirlby, Boltby, Balk, Hawnby and parts of Bilsdale was staggering in its ferocity. Happily, no human lives were lost, but houses, businesses and churchyards over a wide area were ruined, with farm and pet animals among the casualties.

This was not Helmsley's first flood of this kind. Certainly over the years, the pretty market town has tolerated minor flooding, often from Borough Beck, but on October 28, 1754, it suffered what was described as "a great and terrible flood of water" from the River Rye.

Eight cattle houses and five dwelling houses were smashed to the ground with 13 cattle killed. Hay and corn stacks were destroyed, several bridges were washed away, including one at Rievaulx, and Squire Duncombe's gardens were demolished. I wonder if that is now the famous walled garden? One man was found alive still in his bed, having been washed a long distance down-river out of his home, and a haystack was bodily moved 150 yards to finish its trip in a convenient close, still upright. A tannery near Helmsley bridge was destroyed, cellars were filled with water and the flood flowed along Bondgate just like a river.

In the West Riding of Yorkshire, the small town of Holmfirth suffered in a similar way. Throughout its history, the River Holme has overflowed to cause problems with which the residents have coped with admirable calm. One report tells of a minor flood in 1821, the only effect of which was "to send people fleeing to their top chambers or to the high ground behind their dwellings, and to keep them up all night in fear and trembling lest worse things should befall them." Earlier, however, the Great Flood of 1777 was so disastrous that a public appeal for financial help was launched to reimburse sufferers and property owners.

By far the worst for Holmfirth, however, was in February 1852 when the dam burst at Bilberry Reservoir, high above the village. The huge wall of water swept away mills at Bilberry and Digley, tore up graves in Holme Bridge churchyard, killed 40 people at Hincliffe Mill, destroyed houses, factories and bridges in Holmfirth and swept away machinery, cattle, trees and other casualties. In all, 81 people lost their lives in that flood.

The tiny village of Langtoft in the Yorkshire Wolds, without a river or stream flowing through it, has also suffered two major floods. The first was in April, 1657, but there are few accounts of it, save that the village was half-submerged. But on Sunday, July 3, 1892, a flood of epic proportions hit Langtoft. More than 7ft of water tore through the village and its level is still marked on house walls.

That Sunday morning was hot and cloudless but, as the day wore on, the breeze dropped and the air became very still and oppressive. Gradually, menacing black clouds were seen moving towards Langtoft and, when they reached the hill behind the village, they spiralled downwards followed by a tremendous crack of thunder and streaks of lightning. Then a huge volume of water was unleashed.

When the cloudburst hit the ground, it tore deep rents in the hillside, looking more like an earthquake than a thunderstorm, and a massive torrent of water roared down the hill towards the village, tearing huge holes in the ground. It swept away haystacks, houses, farm buildings, walls, hedges and livestock. A hailstorm followed but, miraculously, no human lives were lost. When I paid a visit, the Sun Inn was displaying a collection of photographs of that unbelievable storm.

In many ways, the Holmfirth flood of 1777 and the Langtoft flood of 1892 were very similar to that of the Helmsley and Thirsk district in June, 2005, so are these storms little more than weather freaks, or are we really experiencing the effect of global warming?

A friend from Barnard Castle was trimming his hedge when he found a large, dark-coloured moth which was simple enough to capture. He was then kind enough to bring it along for me to examine, having identified it in the meantime.

It was a female goat moth, a large insect with a wing span of almost four inches. She was beautifully marked in shades of grey and brown, with a furry head and long antennae, and was surprisingly docile in her temporary home of a clear plastic box from a domestic freezer. During the trip from Teesdale to our house, however, she had proved her femininity by laying scores of eggs. When my friend left the insect with me, she had produced about 30, but by the following morning there were more than 70. I believe she was capable of laying more than 300.

I felt the wisest thing would be to allow her to have her freedom before she produced any more, so, late one evening, we encouraged her to leave us. She was gone by next morning. I decided to place the clutch of eggs in as natural a location as possible, choosing a deciduous woodland with plenty of rotten trees. Goat moths lay their eggs on the bark of trees like the elm, ash, lime, oak and poplar, although fruit trees are also favoured. Lifting the tiny, pearl-like, green eggs from the sides of their temporary home with a length of sticky tape, I carried them to safety in a nearby woodland and stuck the tape behind the bark of a fallen tree.

The caterpillars hatch after a week or ten days and then burrow into the rotten wood, where they can live for up to four years if birds like woodpeckers don't find them. These fat and juicy caterpillars are prime targets for hungry birds, which might explain why they spend so much time hiding in rotten trees. Not surprisingly, they are often known as carpenter worms. The fully grown caterpillars can reach four inches (10cm) in length and it is their unpleasant smell, like that of a goat, which has given this insect its name. In the past, some people thought the moths were the main food for goatsuckers - nightjars - but I don't think this has been proven.

In reality, the moths are rarely seen and only live for about a month, having no mouth by which to feed. They live on accumulated reserves which they gathered while a caterpillar. There is a suggestion that these caterpillars will harm living trees by their burrowing activities and, although there are tales of large numbers of them living together in a single tree, it is equally likely that most will fall prey to woodpeckers and other predators.

And finally, if you have not already done so, last Wednesday was the time to plant your cucumber seeds, July 6 being Cucumber Day. "Plant cucumber seeds on sixth July and you'll have cucumbers wet or dry", or so they say.