AS the autumn nights grow longer, most of us are wise enough not to leave our house windows open with the lights on because this can be guaranteed to attract moths into the building.

Although we tend to regard moths as night-flying insects, however, lots can also be seen during the daylight hours, a few daytime-flying species being very beautiful and even spectacular.

Most night-flying moths are somewhat drab in their colouring, often with an ability to merge into the background if they rest on leaves or tree bark.

With more than 2,000 species of moth in Britain, it's not surprising they are difficult to identify and some look remarkably like butterflies, although there are some easily recognisable differences.

One fairly obvious distinction, when viewed at close quarters, is that the moth's antennae don't have knobs at their tips like those of butterflies, the antennae of many moths also being feathered.

Another very clear distinction is that when a moth is at rest, its wings are held down over its body or else extended flat. A butterfly at rest will fold its wings above its body.

With such a variety of moths in this country, it's not surprising that some are very large and others very small. For example, the death's head hawkmoth has a wing span of 5in (14cm). This can be terrifying, more so when the skull-like image on the back of its head is visible!

Some tiny moths have wing spans of only an eighth of an inch (3mm), indeed some also have clear wings, like flies.

One of the most spectacular in the clear wing group is the hornet moth, which flies during the day but is very easily mistaken for a wasp or hornet.

Its body is ringed with black and yellow, its shape is very like either of those insects and it is similar in size. It's not surprising that birds avoid this moth, but in fact it is quite harmless and cannot sting - an ideal camouflage in other words.

In similar vein, the broad-bordered bee hawkmoth, with its clear but marked wings, looks remarkably like a large bee and will even hover over flowers to obtain nectar.

On the topic of spectacular moths, a colleague from Hovingham noticed a most unusual one during our beautifully warm month of September - September 20, to be precise.

This was a humming-bird hawkmoth, which likes the warmth of summer days as it visits brightly coloured flowers to feed. Like the broad-bordered bee hawkmoth, it will hover near flowers so that it can insert its long proboscis in order to drink the nectar.

This moth's name is very apt because, like that curious little humming bird, it whirrs its wings at such high speed when hovering that they become invisible while also producing a light buzzing sound.

Some experts claim that women are more likely to hear that high-pitched sound than men, but I've no knowledge of any evidence to support this - except it was a woman from Hovingham who spotted this local visitor.

The fact the humming bird hawkmoth was seen that far north is, in itself, worthy of note. This is a rare moth for Britain, with only a handful being seen during each year and then usually in the south or west of England, although they are known to venture further north on occasions, even into Scotland.

My records tell me that, although only 50 or so are seen each year in our countryside, some 4,250 were noted in 1947 - a year remembered for its appalling winter and good summer. This year's summer was exceptional too, which might explain why this fascinating moth decided to visit North Yorkshire.

There are lots of hawkmoths, some with wonderfully coloured markings on their bodies and wings. One of them, the privet hawkmoth, is likened to a sphinx because of the way it folds its wings along its body.

The puss moth produces a caterpillar which has a cat-like face bordered with red and black which it will show to predators in a most aggressive manner, while the delightfully fluffy white brown-tail tussock moth produces caterpillars which can devastate woodlands by eating the leaves of most kinds of tree. Pretty though it is, it is not very welcome!

The world of the moth is much too complex and much too interesting to portray effectively in a short article of this kind, but each of our many species has its own characteristics, habitat and lifestyle.

So next time you encounter a moth, try to ascertain its size, shape and colouring, from which a little modest research will produce a name.

Don't be like people of recent times who collected moths - not by keeping them alive or recording their presence, but by catching and killing them, then pinning their remains on a setting board placed in a display cabinet.

A marvellous walk along the Cleveland Way via the cliff tops between Staithes and Skinningrove took us over Boulby Cliff, the highest in England at 690ft (209m) and past some atmospheric reminders of a former industry.

Alum was mined at several sites around the North York Moors and along the North Yorkshire coastline, sometimes with dramatic effect.

Along this coastline were some 20 sites where alum was processed. They stretched from just north of Loftus down to Ravenscar near Scarborough with further sites inland, such as Carlton Bank near Stokesley and Thimbleby near Northallerton.

It is said that the alum discoveries of this region were England's earliest chemical industry.

Alum was discovered in the Cleveland Hills in about 1595 by Sir Thomas Challoner of Guisborough. He had been astute enough, on a visit to Rome, to notice that the discolouring of leaves on trees near the Pope's alum works was very similar to those near his home.

He realised the clay of both regions was also similar and this led him to examine the possibility that the Cleveland Hills might be a source of this valuable chemical.

And so it proved. In opening his mine at Belman Bank, Sir Thomas effectively set himself up in competition with the Pope because the Pope was charging England £52 for a ton of his alum while Sir Thomas could produce it for a mere £11 per ton.

Not only that, one of the enduring tales of his early endeavours was that Sir Thomas desperately needed skilled workers to both mine the alum and teach others their skills, so he bribed some of the Pope's staff to come to England, smuggling them secretly out of Italy in large casks. Needless to say, he was not very popular with the pontiff!

This led to a boom, with workers flooding into the area, and more alum was discovered both in the moors and along the cliffs, with two of the largest mines being established in 1615 on the cliffs both at Boulby and to the north of Loftus.

It was those sites we passed during our walk, pausing to look at the curious smooth covering many feet below and the sad remnants of industrial buildings.

It is difficult to imagine how men managed to work on such a site and in undoubtedly dreadful conditions. And how did they get all their equipment down there?

Not far to the south, of course, was another large mine at Kettleness. Not only was there an alum mine here, however, but also one producing iron ore.

On December 17, 1829 the cliffs around the iron ore mine collapsed, having been weakened by the excavations, and the entire village slid slowly but inexorably towards the sea.

Fortunately, there was an alum ship standing off shore and most of the residents managed to get safely aboard, but the sliding earth carried away both the village and the alum works.

The alum works were rebuilt in 1831, but then caught fire and burned for two whole years.

One curious spin-off resulted from alum mining along those cliffs. It was the discovery, at Kettleness in 1857, of skeletons of long extinct creatures, which at the time led to a belief that dragons and monsters truly existed.

And so they did, except they were the remains of an ichthyosaurus and a plesiosaurus. This matched an earlier discovery in 1824 of the fossil remains of a teleosaurus at Saltwick, near Whitby. Now, of course, potash is mined in that same region, but that's another story.