He was thinner than any of them, and much more serious. Phil was inclined to be frightened of him at first, but soon found him as kindly as the rest. He smoothed Phil's hair for him as if he were a son of his own, and asked to look at his teeth. "H'm," he remarked thoughtfully. "They won't be much use for felling trees, but I daresay you can help us in other ways. We must set to work in the early summer," he continued, turning to Mother Beaver, "for there is a lot of rebuilding to be done this fall." "Rebuilding?" echoed Phil. He had loved his bricks, and to make castles in the sand; building those dome-shaped houses must be great fun. "Certainly," replied Father Beaver. "Our dam must be enlarged, and a new lodge put up. We shall want all the help we can get. Later on, when we have got up our strength, we must begin to cut those saplings." Phil was feeling rather tired, so, while the young Beavers started another game, he sat with their parents, trying to understand what they meant when they spoke of "IT." "I feel sure IT is somewhere about," said Father Beaver moodily. "I came across ITS traces two or three miles away." Mother Beaver sighed. "There is no use in borrowing trouble," she said. "We must just keep a sharp look-out, and get our work done quickly. I'm glad now that we made those extra holes in the bank, though it did seem rather unnecessary at the time." "Those holes, my son," said Father Beaver, in answer to Phil's inquiry, "lead to the deep tunnels in which we take refuge when we are pursued by our enemies. There we are comparatively safe, but in the open country or in the woods, owing to our clumsy movements on land, we are at their mercy." His voice was gloomy, and it made Phil sad to think that such gentle animals as beavers had enemies. "If they catch you, do they swing you up high, and make you all sick and giddy?" he asked, with a vivid recollection of the terrors of the barn. "Worse," said the Beaver, shortly. "The hunters trap and kill us for our valuable fur, and IT--the Wolverene--actually eats us! This is why we go to so much trouble to make our houses secure, so that when the frost has hardened the thick layer of mud which we place each fall over the thatch of stones and driftwood, neither teeth nor claws can penetrate the hard surface." Mother Beaver had shuffled off to her young ones, who were making up for the short commons of the winter by eating all the green shoots that came in their way. Their father, settling himself comfortably in the shelter of a low bush, invited Phil to sit beside him and have a chat. "You want to learn our ways," he said, looking at him indulgently. "They are easy to understand, for though we are more skilled in building, perhaps, than other creatures, it is chiefly for our industry that we are noted. Nature has taught us to think ahead and provide for the future. I suppose you know what 'thinking ahead' means?"