What Am I Riddles

Question: There is an ancient invention still used in some parts of the world today that allows people to see through walls.What is it?

Question: You use a knife to slice my head and weep beside me when I am dead.

What am I?

Question: Alone I am 24th, with a friend I am 20. Another friend and I am unclean.What am I?

Question: I am greater than God, more evil than the devil, the poor have me, the rich don't, and if you eat me, you'll die.What am I?

Question: With pointed fangs I sit and wait, with piercing force I serve out fate. Grabbing bloodless victims, proclaiming my might; physically joining with a single bite.What am I?