Happens here in Australia too. Probably because it isn't that common and kids with red hair generally look different, so its the usual reasons there. In adults its just half hearted teasing, nothing serious
why is it that there is a shitload of redheads in britain and they get teased, but there are loads fewer of them elsewhere and they are seen as cool and interesting and hot?
No idea, but here mainly adult men are teased lightly about it, with names like Bluely and Bloodnut.