Answer:
Iām white; perfect for cutting & grinding. For most animals I am a useful tool.
I've been argued on my color. Without me you'll die. So many attempts on your life use me so make sure you have many of my White friends.
I have a little pool with two layers of wall around it. One white and soft and the other dark and hard. Amidst a light brown grassy lawn with an outline of a green grass.
Squeeze me and I cry tears as red as my flesh but my heart is made of stone.
What has four wheels and flies?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.