It doesn't bark, it doesn't bite but it still won't let you in the house. What is it?

My body has a dozen heads or more, My tails don’t wag when you walk in the door. Count the ways you can hold me tight, Or use me for a special night! What Am I?

I am black of eye and bright of hair And my feet are firmly in the ground. I love the sun upon my face And I follow it around. When I am dead and gone tis said, That I will droop real low, That I will keep the birds well fed, Standing stiff there in my row. What am I?

I had but one eye and a long tail which I let fly. Every time I went through a gap, a bit of her tail I left in a trap. What Am I?

With pointed fangs it sits in wait, With piercing force it doles out fate, Over bloodless victims proclaiming its might, Eternally joining in a single bite. What am I?

A bat and a ball cost $1.10. The bat costs one dollar more than the ball. How much does the ball cost?

You can see me in water, but I never get wet. What am I?

I have many teeth and sometimes they're fine, first I'm by your head, then I'm down your spine. What am I?

A woman is sitting in her hotel room when there is a knock at the door. She opened the door to see a man whom she had never seen before. He said "oh I'm sorry, I have made a mistake, I thought this was my room." He then went down the corridor and in the elevator. The woman went back into her room and phoned security. What made the woman so suspicious of the man?

There is one word that stands the test of time and holds fast to the center of everything. Though everyone will try at least once in their life to move around this word, but in fact, unknowingly, they use it every moment of the day. Young or old, awake or in sleep, human or animal, this word stands fast. It belongs to everyone, to all living things, but no one can master it. The word is?