The explorers belonging to the nest scour the surrounding country in search of the material needed by the farmers, and following their indications, the road-makers clear paths a quarter of an inch in width and frequently a mile in length, through the immense tangles of the tropical forests,--roads as straight and useful as those of the Romans. Along these the farmers pass, often at the end of it to climb a tree fifty feet high in search of the bits of flower petals, with which they pass so continuously to the nest that the human observer will sometimes see what appears to be a thin trickle of pink or yellow through the jungle grass as far as the eye can reach. These flower petals are packed in the city's cellars, moistened, and sown with the spores of a minute fungus upon which the ants live. Most curious of all is that these ants also keep pets--several varieties of tiny insects which they feed and protect, and which apparently serve no purpose save to give pleasure by their playful gambols. In every well established city of the parasol ants there resides a small green snake in a chamber built about him by the ants themselves, who feed and guard him, and when by any accident the little reptile is removed they abandon all their affairs until another is found to replace him. Unless this snake serves them as a fetish or deity there is no means of accounting for their desire for his presence, for as far as can be discovered he fills no purpose of utility. Mark Twain declares that the ants "vote, keep drilled armies, hold slaves and dispute about religion," and for all we know this little snake may be the centre of a complex system of theology.