So to become obedient servant and to have no discrimination of sex and food, that means dogs, and they are not human beings. And camel, although he is a big animal, he takes pleasure in eating his own blood. How is that? You will find the camels are very fond of eating thorns. So the thorns they eat, and the thorns cut the tongue, and the blood comes out. It makes a taste, and he is thinking that the thorns are very tasteful. That is camel. Similarly, we are everyone camel because we are enjoying sex. What is this sex?
I am spoiling my blood. One drop of semina is created by sixty drops of blood. That is scientific. So when one discharges this semina, he thinks he is enjoying. He does not know that he is spoiling his blood. That is camel. He thinks he is enjoying. He does not think that "I am spoiling my blood. And if I spoil my blood more, then I shall be attacked with so many diseases, I will lose my resistance power." He does not know. But he thinks that sex enjoyment is very nice. It is not nice at all.
Prabhupada's lecture - Śrīmad-Bhāgavatam 1.3.9 - Los Angeles, September 15, 1972