I prefer if my housemates ignore me.I don't know about you but I like my space and privacy.But we do communicate sometimes if we stumble upon each other in the kitchen or somewhere.Usually I'll start with "hi,dah makan?".If you want to start a conversation,you can say that or "are you going back to hometown this holiday" or something like that.If the other party doesn't respond,then just ignore them.Don't take it personally,be yourself.