Answer:
Santa shakes his belly like a bowl full of me
The more you have me the less you see. Shine a light on me and I shall flee.
I have wheels and flies yet I am not an aircraft.
I'm as simple as a circle worthless as a leader; but when I follow a group their strength increases tenfold. By myself I'm practically nothing.
My first is second in line; I send shivers up your spine; not quite shining bright I glitter in the light.
No matter how little or how much you use me, you change me every month.
What am I?
Animal
Difficult
Easy
Food
Funny
Kids
Logic