"Locana dasa Thakura says, 'My dear brother, you just try and examine this. Within the three worlds there is no one like Lord Caitanya or Lord Nityananda, because Their merciful qualities are so great that They make even birds and beasts cry, what to speak of human beings.' Actually, when Lord Caitanya passed through the forest known as Jarikhanda, the tigers, elephants, snakes, deer, and all other animals joined Him in chanting Hare Krsna. It is so nice that anyone can join. Even the animals can join, what to speak of human beings. Of course, it is not possible for ordinary men to induce animals to chant, but if Caitanya Mahaprabhu could inspire animals to chant, at least we can encourage human beings to adopt this path of Hare Krsna mantra chanting. It is so nice that even the most stonehearted man will be melted. Pasano means stone. It is so nice that even stone will melt."
(From Sri Sri Gaura-Nityanander Daya by Locana Dasa Thakura, Purport by Srila Prabhupada)