Why do you have to wash your hands after you have been in a forest?

My grandmother went for a hike in in a woods in Maryland and the sign said “Make sure you wash your hands after you come back home, because there could be ticks on you!” And I’m confused on why you need to wash your hands. Like... where would the ticks be? I don’t get it.<br><br>Edit: I know you have to shower but I don’t get why I have to specifically wash my hands... like are ticks just gonna be on my hands for no reason?