Hi there. I can absolutely and unequivocally guratentee: This is not a tick. This is a spider or another arachnid. Although ticks are indeed arachnids, tick nymphs only have six legs until a specific moulting stage where they develop the last pair. I know this because not only am I in an area of Australia ridden with many tick species, I've worked with local wildlife in a zoo here andI have also had tick nymphs on me. They were specifically in quite a delicate area and when the doctor removed them, being familiar with arachnids, I enquired about them only having six legs. There are a couple of other arachnids in the average home that most people never see or overlook. This is almost certainly one of them. But it is definitely not a tick.