In most countries would be travellers may ask about there being a problem with mosquitos

and in Britain this would usually result in rarely in most places will mosquitos be a bother

But this may not be so if you are in your early 20s or younger as you may encounter the DREAD Mosquito in places like shopping centre, parks, outside stores, housing flats, in city centres, etc.
This mosquito is no skeeter like you think but a noisemaker that emits an obnoxious mosquito like buzz but only at incredibly high frequencies that only folks in their early 20s and younger can pick up

and pick up they do this sound that's been described as being so horrible and loud young folk have to move out of the site, which is the purpose of the mosquito - keeping anti-social and young folk from gathering in places like shopping malls, etc.
These 'teen repellents' have been decried by Children's Watchdog groups in England, Scotland and Australia where they have been deployed now for a few years

England's government-appointed Children's Commission has proposed a ban, arguing that the weapon infringes on the basic rights of young people and calims it could perhaps hve unknown long-term health effects.

Apparently though the noise can be heard by animals and babies it only causes intolerable noise in folks older than 12.

So families visiting Britain with kids over 12, if you child suddenly clutches their ears and is in agony you know there's a skeeter on the lose.

If you have seen groups of 40-50 teenage hoodies hanging around a shopping centre after dark, then you might sympathise as they can be very intimidating, even if not intending to do so.

However , to quote a phrase I saw earlier, I am more on divided than a lib dem at a legalise cannabis debate held in a shed wharehouse.

If shops decided that pensioners were a problem (Blocking the post office entrance, sitting for hours at the coffee shop with one cup of tea, racing around on mobility scooters etc) and brought in a device to discourage the elderly, there would rightly be outrage at the descrimination.

An interesting article on these:

http://www.bbc.co.uk/dna/h2g2/A31699146

From the article, suggested alternatives, if it gets banned...

"Playing classical, or indeed any uncool music is one option. Another is the installation of sodium 'zit lights', which embarrass youngsters by highlighting their acne. Norfolk police have also deterred teenagers from stairwells by spraying them with Jeyes Fluid2 - the stairwells, that is, not the teenagers."

Thank god I'm not a teenager now. They have been thoroughly 'demonised' here in the UK - 99% of the time very unfairly.

What? I am for sure out of the teenage loop!!