what do you mean as rights?? As to buy the house from you or something, force you to sell?
Tenants do have rights, but at the end of the day it is your house. You cant just evict them for no reason, but if you planned to either sell the house, move into it yourself or they gave you reason to evict them ( not likely after 8 years of being fantastic ) then if you did it all legally then they would have to move out.
Are you maybe thinking of other stories. I remember a while back there was a plot of land in I think the Ballymum area that was owned by the council, but a family had been living on this land for like 20 years without the council doing anything, it was eventually ruled that the family did have rights to this land because they had been allowed to live their for so long. this is totally different to what situation you have, so dont worry.