Good Riddles

Question: Four hikers are forced into a cabin with no lights by a bad storm. On the door of the cabin is a sign that reads, "Come in as you please, but fall asleep and you will die." Being very superstitious, they all take this very seriously and devise a plan so they can all stay awake. They all stand in a corner and one person walks from one corner along the wall to the next and taps the person in that corner making sure they are awake. They do this for many hours until one hiker suddenly runs out of the cabin screaming along with all of the others.Why did they run out terrified?

Question: What is brown or silver, has a head and tail but no arms or legs?

Question: I have a few points but we're not competing.
And I'll help you win when you're eating.

What am I?

Question: It brings light to a dark dark world,
In a current it travels and through tunnels it's hurled.
Touch it and it'll kill you.

What is it?

Question: You fill up a bathtub with water and you have a teaspoon, tablespoon, and fourth cup. What is the fastest way to empty the bathtub?