Answer:
What invention lets you look right through a wall?
I jump when I walk and sit when I stand.
With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?
I am the tool for inspiring many. Buy me in the store for not much more than a penny. Don't overuse me, or my usefulness will go. What am I?
I belong to you but others use me more often than you do. What am I?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?