FOR a drive in the country next month, every motorist should have one. The splatometer should be as essential a piece of kit as a spare wheel or a rear view mirror.

Not only that, it's free.

For yours, simply contact the Royal Society for the Protection of Birds and it will pop one in the post.

It should be swiftly pointed out, the idea is not to see how many pheasants you can run over or how many times dive-bombing gulls decorate your paintwork with diarrhoea.

The aim is to see how many bugs you squash on your journey.

Because birds feed on bugs and the people at the RSPB are setting out to find if the declining numbers of certain bird species are matched by there being fewer bugs about.

To that end, the organisation has produced the splendidly named splatometer.

It takes the form of a cardboard grid that helps you work out how many bugs you've splatted during a car journey. Preferably one of between 20 to 80 miles in dry weather.

Simply wipe your front number plate clean before you start out, note the car mileage or set the trip meter and, when you return, place the grid over the number plate and count the number of splats in each square. Also work out the length of the journey.

Fill in the form and return it to the RSPB. A nationwide picture of bug numbers should then emerge.

That's the theory anyway and so serious is the research involved that June 2004 has been designated the month of the Big Bug Count.

"Many birds rely on insects during the summer to feed themselves and their chicks," explained Andy Waters of the RSPB, who rejoices under the heady title of Big Bug Count spokesman.

"If insects are vanishing it could explain why birds such as sparrows are dropping sharply in numbers, he added.

"Insects are vital food for many birds like swallows, house martins and house sparrows.

"Who could believe that house sparrows would decline by two-thirds in the last 25 years. By taking part in the Big Bug Count you'll be helping us look at how declines may be affecting some of our best loved birds."

In an effort to stop people getting squirmy about bugs and improve their public image a bit, the RSPB has produced a series of "Do You Know" facts about them.

For example, do you know:

n There are more than 23,000 insect species in the UK and at least eight million worldwide.

n Bugs are essential for pollinating crops.

n Bugs are vital recyclers. They break down dead organic matter and recycle nutrients on farms, in gardens and in the wild

n Insects provide food for birds, reptiles and amphibians

n They are particularly important as food for growing chicks.

n Insects are important in medical and genetic research.

n We also have insects to thanks for honey, silk and beeswax.

So that's the PR side of bugs. However much you might hate an annoying blue bottle or a swarm of midges, everything has its place in the great scheme of things and that's why counting the splats on your car's front number plate could save a swallow.

n Further details and forms for the RSPB Big Bug Count can be obtained either from the website www.rspb.org.uk/bugcount or by phoning 0870 7875577