"I'll explore one of their tunnels," thought Phil. He dived into the river, using his right leg instead of a tail to splash the water as the Beavers did, and soon found a Beaver's hole. "Anyone at home?" he sang out gaily, as he ran through the tunnel's twists and turns. "We're here!" cried Mother Beaver from its innermost recesses; and there Phil found her with her young ones, looking most forlorn. "What is the matter?" he asked, for he had never seen her so distressed. She was shaking all over as she told him, and her voice was broken with sobs. The night before, it seemed, almost immediately after Phil had left them, the Wolverene had made an unexpected attack. All had seemed safe, and the Beavers had for a moment relaxed their guard. Dropping from the branches of a tree into their very midst, the Wolverene had pounced on a plump young Beaver just then engaged in felling a willow sapling; in spite of his struggles there had been no chance for him, and the Wolverene had eaten him then and there. Not content with this, he had taken his stand upon the river bank, intent on further prey. The young Beavers were trembling still, and even the bravest of their elders were afraid to venture out from their retreat. When Mother Beaver heard what had happened to the Wolverene in the early morning, she could scarcely contain herself for joy, and Father Beaver, who had sought his family in vain in the winter houses, where many of the colony had taken refuge, would have embraced Phil had he known how. He straightway planned a wonderful new dam that should put the old one to shame; and the number of trees the Beavers felled that night was simply marvellous. Nowhere along the river banks were more contented creatures than they; and many a timid wood thing, unknown to them, shared their thanksgiving that the Wolverene was dead. Father Beaver was interested to learn from Phil of the Hackees' narrow escape. "We have all our foes," he said, "and must fight them as best we can, with our wits or our teeth, the weapons Nature has given us. That Stoat you saw will perhaps be trapped this winter; his brownish coat will turn pure white when the snow comes, and he will be called an 'Ermine' instead of a 'Stoat'; and then the hunters will be after him." "Then the Ermine and the Stoat are the same creature?" cried Phil in amazement. "The very same," said Father Beaver, "and Ermine fur is more valuable than our own. All sorts of traps will be set for him, for as his coat will be the same colour as the snow, it will be almost impossible for the fur hunters to take him in any other way." "I wonder _why_ his fur turns white in winter?" Phil said, thoughtfully.