The senses are compared to venomous serpents. They want to act very loosely and without restriction. The yogī, or the devotee, must be very strong to control the serpents – like a snake charmer. He never allows them to act independently. There are many injunctions in the revealed scriptures; some of them are do-not’s, and some of them are do’s. Unless one is able to follow the do’s and the do-not’s, restricting oneself from sense enjoyment, it is not possible to be firmly fixed in Kṛṣṇa consciousness.