What has many keys but can’t open a single lock?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

He does not have any heart but still, He manages to live.
If you kill him, you will eventually die but yet you kill him.
He cannot run, who is He?

I am soft and cuddly that soothe your heart. But, If you pick my last name I am going to tear you all apart. Who am I?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

Which is the correct shadow of the bird?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

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