I have noticed that, nowadays, (though it might be where I live) woodlice do not curl up any more when challenged. I grew up in Hampshire, in the 40s and 50s, where they did.
Some species of woodlice roll up (generally known as pill woodlice, I think because when rolled they are about the size and shape of some sort of pill), but many species don't. As far as I know, of the 37 species of woodlouse found in Britain, only 7 can roll up.
The most common and widespread pill woodlouse is Armadillidium vulgare. This is frequest in the south and east of England, especially in chalk or limestone areas, and would certainly be a common sight in Hampshire. You don't say where you live now, but if you have moved further north or west then pill woodlice may not be in your area, and what you are now seeing will be one of the other species.
Entomologist and biological recorder
I certainly don't see as many of the type that curl up as I used to.