A man dies of old age on his 25 birthday. How is this possible?

I travel all around the world but always stay in the corner. What am I?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

I have branches, but no fruit, trunk or leaves. What am I?

We are a group of eight brothers. We consider the weak, yet we protect the king in every battle. If we move ahead, we never turn back. Who are we?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

Can it be possible to build a house that has all its four walls facing towards the South?

Only one colour, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?