Pikeys in their truest form are a people that roam the land (Britain) in moderate to large numbers looking for appropriatley sized open spaces to park their trailers and set up a temporary home, usually on private property but occassionally on land leased/sold to them by land owners or allocated to them by councils (local government in Britain).
When the temporary encampment is set up, you will notice their presence immediately because of the eye sore that is fifty to several hundred mobile homes, trailers, vans and cars taking up space that was previously devoid of anything.
Once set up, pikeys are notoriously difficult to move on, often claiming persecution/discrimination/ownership of land when asked to move on, when in fact
it is their abuse of local resources and amenities (schools, shops, pubs) that leads to their being asked to leave.
Once moved, the land they previously inhabited for anything up to several years will be completely unusable by anyone until renovation is undertaken by local council or land developer, as pits dug in to the ground and used as latrines are common along with large piles of massively unhygeinic rubbish and/or several (possibly stolen) cars or vans now no longer needed in their endeavours to completely fuck up anything in sight will be left behind as testimony to their parasitic nature.
Pikeys are closely linked to, but not be confused with traveller