Best short riddles

Which is the rope you never skip with?

What loses its head in the morning but gets it back at night?

What is the major difference between a lighting and electricity?

What has no beginning, end, or middle?

Which insect is the best in games?

Can you arrange four 9's and use of at most 2 math symbols, make the total be 100?

What type of cheese is made backwards?

Why didn't the hot-dog star in the movies?

What's three stories tall and moves at 15 mph through the jungle?

The digits 0-9(0,1,2,3,4,5,6,7,8,9) can be rearranged into 3628800 distinct 10 digits numbers. How many of these numbers are prime?