While instructing Śrīla Rūpa Gosvāmī on the science of devotional service, Lord Caitanya discussed in some detail the material world and the living entities. He pointed out that among the 8,400,000 species of life—900,000 species of aquatics, 2,000,000 kinds of plants, 1,100,000 varieties of insects, 1,000,000 species of birds, 3,000,000 kinds of beasts, and 400,000 species of humans—Homo sapiens are clearly in the minority.