Every living being has a particular characteristic that is visible in all kinds of forms of living being. That is service.
Everyone is rendering service. Here we have so many ladies and gentlemen present, but every one of us is rendering some service to the superior. That is our position. The animals also, the inferior animals, they are rendering service to the superior animal. The superior animal is eating the inferior animal, jīvo jīvasya jīvanam (SB 1.13.47). Big snake is eating small snake. There is a verse in the Śrīmad-Bhāgavatam, apadānam catuṣ-padām.
Those who are two-legged, they are eating the four-legged. And the four-legged animals, they are eating who cannot walk. Apadānam catuṣ-padām. Those who cannot move—just like grass, plants, trees, they cannot move—they are being eaten up by the four-legged animals. And the four-legged animals are being by . . . eaten by the two-legged animals, human being. Just try to understand how this weaker section is serving this stronger section. That is the law of nature. Jīvo jīvasya jīvanam. One living entity is the food or . . . living means for another living entity, by nature's law. So the conclusion is that we must serve . . . must render service to the strong. This is nature's law.