Riddles about animals

Why do birds fly south in the Fall?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. I am a...

I live in the ocean. I move slowly. I eat clams. I have five arms. I am a...

I have four legs. I am a pet. I hate cats. I bark.

I hiss. I can be poisonous. I am long. I have a forked tongue. What am I?

Someone said you sounded like an owl.

I eat other animals. I have a big mouth. I am green. I live in the water. Who am I?

I had no father, only a grandfather. I shall bear no sons, only daughters. What am I?

I sleep when you are awake, I am awake when you fall asleep. I can fly but no feathers to aid my flight. What am I?

A petshop owner had a parrot with a sign on its cage that said "Parrot repeats everything it hears". Davey bought the parrot and for two weeks he spoke to it and it didn't say a word. He returned the parrot but the shopkeeper said he never lied about the parrot. How can this be?