When you take the animal to the slaughterhouse for killing, he cries. Why? Because he's feeling pain. He knows that, "I'm going to be killed." So there is soul. Soul is there. You don't think that soul is not there. Soul is there. Therefore, a Krishna conscious person who has realized God, he is samah sarveshu bhuteshu, he's equal to all living entities. He'll feel pain even for cutting a tree. He'll feel pain, he'll feel pain even he traverses over an ant.
There is a story that one hunter, he was killing in the forest all kinds of animals, and he was killing them half. So they were suffering too much severe pain. So Narada Muni was going in that way. He saw that these animals have been half killed, and they are so much suffering. Who is doing that? So he searched out the hunter. He requested, "Sir, you are killing the animals. Why don't you kill them all at a time? Why you are killing half? They are suffering. You'll have to suffer in that way." The hunter did not know that killing animals is sinful and he has to suffer again. So he said, "Sir, I am trained like this by my father. This is my profession. I do not know what is sin. But this is the first time I am hearing from you that killing this animal, especially in this way, is very much sinful."
So because he saw a saintly person, he got his sense. He asked him that, "How I can get rid of this sinful life?" So Narada Muni suggested that, "I shall give you the way how you can become free from this sinful life." So he made him a disciple and asked him to chant this Hare Krishna mantra and sit down on the bank of the Ganges, and the hunter said, "Sir, where shall I get my food?" Narada Muni said, "I'll send you, don't bother. I'll send you food." So the village people, when they understood that the hunter has become a saintly person, so everyone used to come and see him. Somebody was bringing some rice, somebody wheat, somebody some sweets, some fruits, some flower. So huge quantity of foodstuff was coming. So in this way, he became a perfect saintly Vaishnava.
Later on, when Narada Muni came to see him, he was coming to receive the spiritual master, jumping over the road. So when the hunter, now he became Vaishnava, Narada Muni and his friend Parvata Muni asked, "Why you are jumping?" He said, "Sir, there are so many ants, so I was trying to save their life." The same hunter who was killing animals one time half-dead and was enjoying, is no more interested to kill even an ant. This is called saintly life. Samah sarveshu bhuteshu. Samah, equal to all living entities. Not that simply protection should be given to the human being.