Short simple riddles

When you don't have me, you want me, but when you do have me, you want to give me away. What am I?

If you see a bird sitting on a twig, how could you get the twig without disturbing the bird?

What goes in dry and hard, but comes out wet and soft?

I have no legs. I will never walk, but always run. What am I?

Four children and their pet dog were walking under a small umbrella. But none of them became wet. How?

I can run, but not walk. Thought is not far behind me. What am I?

Physicists have built devices to move me very fast. My last seven letters can be commonly found in newspapers, magazines and journals. What am I?

Which vehicle is spelled the same forwards and backwards?

I am small. I can be scary. I have eight legs. I spin a web. What am I?

How can you leave a room with two legs and return with six legs?