What am I riddles

I have four legs and a tail. I have no teeth. I can swim and dive underwater. I carry my house around with me. I am a...

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

I live in lakes and rivers. I eat fish and birds. I have four legs and a long tail. I have lots of pretty teeth. I am a...

I am a white box having no key or any lid. Yet there is a golden treasure inside it. What Am I ?

You can break me easily without even touching me or seeing me. What am I?

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

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?

I am a nut with a whole. What am I?

I am a mother and a father, but have never given birth. I'm rarely still, but I never wander. What am I?