I do believe that animals have a lot of the same instincts as us humans. They all have hunger, they all thirst, they all procreate, they all love and they all hurt just like us. Now onto why I believe this....
Several years ago I was renting a studio that was built on the back of a house, there was a nice yard and a small spot to grow some garden goodies. It was not a big spot but enough to grow some tomatoes. When the tomatoes sprouted I kept noticing that the insides were being pecked out while they were still green. I had originallt thought it was some kind of bug so I asked a friend about this. He looked at the plants and said that it was birds pecking the insides and probably a blue jay.
I asked him what I could do to keep them off my plants and he said shoot them ! So I barrowed a pellet rifle and waited on my porch for the sucker to come down and eat my tomatoes, sure enough it was not long and the little bird landed and the tomatoes cage and blammo I shot it dead er than a door nail. The bird fell over onto the ground and I left the dead bird there for others to see that this is what happens to those who tread on my tomatoes. What I learned very fast was that there was another bluejay in the tree and this other bird squaked for hours as if it was mourning the loss of it's lover.
Needless to say it had made me sad because I know what it is to loose a loved one and I suffered for a long time in my heart about that other bird loosing it's mate. To this day I don't kill anything unless I plan to eat it, even a bug or spider which I hate most of all, I will not kill. If it is my house I respectfully capture it and set it free to the outside. I CAN NEVER FORGET THAT BIRD MOURNING