There is no mercy among insects. Only the web-spiders sat unmoved and immovable in their colossal snares, secure in the knowledge that their gummy webs would discourage attempts at invasion along the slender supporting cables. Surging onward, flowing like a monstrous, murky tide over the yellow, steaming earth, the army ants advanced. Their vanguard reached the river, and recoiled. Burl was perhaps five miles distant when they changed their course, communicating the altered line of march to those behind them in some mysterious fashion of transmitting intelligence. Thirty thousand years before, scientists had debated gravely over the means of communication among ants. They had observed that a single ant finding a bit of booty too large for him to handle alone would return to the ant-city and return with others. From that one instance they deduced a language of gestures made with the antennae. Burl had no wise theories. He merely knew facts, but he knew that the ants had some form of speech or transmission of ideas. Now, however, he was moving cautiously along toward the stamping grounds of his tribe, in complete ignorance of the black blanket of living creatures creeping over the ground toward him. A million tragedies marked the progress of the insect army. There was a tiny colony of mining bees--Zebra bees--a single mother, some four feet long, had dug a huge gallery with some ten cells, in which she laid her eggs and fed her grubs with hard-gathered pollen. The grubs had waxed fat and large, became bees, and laid eggs in their turn, within the gallery their mother had dug out for them. Ten such bulky insects now foraged busily for grubs within the ancestral home, while the founder of the colony had grown draggled and wingless with the passing of time. Unable to forage herself, the old bee became the guardian of the nest or hive, as is the custom among the mining bees. She closed the opening of the hive with her head, making a living barrier within the entrance, and withdrawing to give entrance and exit only to duly authenticated members of the extensive colony. The ancient and draggled concierge of the underground dwelling was at her post when the wave of army ants swept over her. Tiny, evil-smelling feet trampled upon her. She emerged to fight with mandible and sting for the sanctity of the hive. In a moment she was a shaggy mass of biting ants, rending and tearing at her chitinous armour. The old bee fought madly, viciously, sounding a buzzing alarm to the colonists yet within the hive. They emerged, fighting as they came, for the gallery leading down was a dark flood of small insects. * * * * *