Answer:
I turn around once. What is out will not get in. I turn around again. What is in will not get out.
My thunder comes before the lightning. My lightning comes before the clouds. My rain dries all the land it touches.
My life can be measured in hours, I serve by being devoured. Thin, I am quick. Fat, I am slow. Wind is my foe.
Voiceless it cries, wingless flutters, toothless bites, mouthless mutters.
What goes in, but never through? I've got some and so do you. We might lend one, or even two, but only if our trust is true.
I am your mother's brother's only brother in law. Who am I?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?