PURPORT

In the Vedas the symptoms of the lower animals are described as follows: athetaresam pasunam asanapipase evabhivijnanam na vijnatam vadanti na vijnatam pasyanti na viduh svastanam na lokalokaviti; yadva, bhuri-tamaso bahurusah ghranenaiva jananti hrdyam prati svapriyam vastveva vindanti bhojana-sayanady-artham grhnanti. Lower animals have knowledge only of their hunger and thirst. They have no acquired knowledge, no vision. Their behavior exhibits no dependence on formalities. Extensively ignorant, they can know their desirables only by smell, and by such intelligence only can they understand what is favorable and unfavorable. Their knowledge is concerned only with eating and sleeping. Therefore, even the most ferocious lower animals, such as tigers, can be tamed simply by regularly supplying meals and accommodations for sleeping. Only snakes cannot be tamed by such an arrangement.