Answer:
I am heavy forward, but backward I'm not. What am I?
What flies without wings?
I run through hills. I veer around mountains. I leap over rivers. And crawl through the forests. Step out your door to find me.
I am carried by mad animals.
I may be made of metal, bone, or wood and have many teeth. My bite hurts no one and the ladies love me. What am I?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.