By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

During a secret mission, an agent gave the following code to the higher authorities
AIM DUE OAT TIE MOD

However, the information is in one word only and the rest are fake. To assist the authorities in understanding better, he also sent them a clue, If I tell you any one character of the code, you can easily find out the number of vowels in the codeword.

Can you find out the code word?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

Which tank will fill first?

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

Count the number of triangles in the picture below:

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

Two in a corner, one in a room, zero in a house, but one in a shelter. What am I?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?