Bored, drunk and angry German wasps are on the rampage across Britain - and likely to sting for no reason.

The worker wasps, which are bigger than the usual variety, have finished tending the hive's queen this summer.

It means the yellow-and-black insects are flying around aimlessly - enjoying themselves feasting on fermented fruit.

But this is bad news for those enjoying the last of the summer rays in Britain's gardens, as they are now 'extra bold' and rather grumpy.

Warning: German wasps have finished serving the hive queen and are flying around aimlessly

Paul Bates, of pest control firm Cleankill Environmental Services, said: 'Worker wasps have finished their life's work as queen wasps have stopped laying and don't need food bringing to them.

'This means that the workers are free to go out and enjoy themselves which includes stealing meat from the barbecue.

'There will also be drunk wasps around who have been feasting on fermented fruit and will be extra bold.

'All this means that the wasps are likely to sting for no reason and they are now at their most dangerous.'

And for those unlucky enough to be on the receiving end of a wasp's attention are certain to know about it.

Mr Bates said: 'The type of wasp causing most problems is the German wasp which gives a particularly painful sting despite its size.'

The news comes after it was revealed this week that the Euro-wasp, called dolichovespula media or median wasp, has been spotted in Scotland for the first time.

The wasp, twice the size of a common wasp with an 'extra painful sting', is about one-inch long and first appeared in England in the 1980s, but has only just now been spotted in Scotland.

There has also been a huge increase in the general number of wasps this summer, which experts have put down to the sunniest April for 86 years.

This may have encouraged nest-building, meaning that many more queens and males are emerging to mate and hunt for food.

Painful: The German wasps are said to be angry and likely to sting for no reason (pictured: common wasp)

The boom in numbers has put beekeepers on high alert for hive attacks. One major tourist venue has even placed notices in its cafe apologising for the wasp menace.

A spokesman for Basis Prompt, which registers pest controllers and monitors council call-outs, said its members were braced for ‘a deluge of calls’ after the unusually sunny spring.

‘The annual wasp population in the UK is very much dependent on weather conditions,’ he said.

THE WASPS ON THE RAMPAGE The German wasp - or vespula germanica - is found in Europe, north Africa and parts of Asia - as well as areas of the southern hemisphere, where it has been introduced by humans. The are hundreds of millions of the German wasps in the UK, although population numbers depend on 'favourable conditions' such as mild winters and dry spring and summers. It can be distinguished from the common wasp by three marks on its face. Advertisement

There were 111,147 ‘wasp control treatments’ by councils last year, an increase of 87 per cent on 2013. The figures for this summer are still being compiled.

Insect behavioural expert Professor Francis Ratnieks, of the University of Sussex, said successful nests increased in size throughout the summer, peaking in September.

‘Wasp numbers fluctuate enormously year by year,’ he said. ‘One factor is probably the weather conditions at the time of nest founding – March to May.’

At the Bentley Wildfowl & Motor Museum in East Sussex, a cafe notice reads: ‘We’re sorry about the wasps. This summer has been a great year for wasps but a dreadful one for picnics. We’re trying our best to keep their numbers down.’

Manager Edward Hill said: ‘We’ve got wasp traps everywhere. It’s a big problem for us because they come after our jam and marmalade.’

Rosemary Taylor, secretary of the Avon Beekeepers Association, said increased numbers would inevitably put more beehives at risk of attack.

Dee Ward-Thompson, of the British Pest Control Association, said: ‘While wasps are a pest, they are important to the balance of the environment.