There are a good many different kinds of owls, several of which are found in both continents. There is the long-eared owl, for instance, which has two rather long feathery tufts upon its head; and there is the short-eared owl, which has short ones. As a rule, these tufts lie flat upon the head. But when the bird is excited they stand upright, and give it a very odd appearance. Then there is the brown owl, which utters that mournful hooting sound which one so often hears by night in wooded districts. Very often as one is walking along a country lane in the evening one of these birds sweeps suddenly by and disappears into the darkness. It is busy searching for mice, and the number which it catches must be very great. For it has been found that when a pair of these birds have little ones, they bring a mouse to them about once in every quarter of an hour all through the night! And, besides that, their own appetites have to be satisfied; and owls seem always to be hungry. One day the late Lord Lilford, one of the foremost British ornithologists of his time, tried to see how many mice a barn-owl really could swallow. So he caught one of these birds and put it in a cage, and gave it seven mice one after the other. Six of these it gulped down without any hesitation; but though it tried hard to swallow the seventh it could not quite manage to do so, and for about twenty minutes the tail of the mouse was dangling from a corner of its beak. At last, however, the tail disappeared; and three hours later the owl was actually hungry again, and ate four more mice! None of the owls ever digest the bones and feathers or hair of their prey; but these materials get packed into balls in the stomach, and after a time are coughed up and thrown away. Very often large quantities of these "pellets" are found in hollow trees in which owls have been roosting, more than a bushel having been taken from a single tree, and by examining them one may learn the character of the bird's daily fare. The birds do not make a nest, but lay their eggs on a heap of these pellets instead; and they have an odd way of laying them at intervals, so that sometimes half-fledged little ones, newly hatched little ones, and freshly laid eggs may all be found together. When the young owls are waiting for their parents to return with a mouse, they always get very much excited and make most odd noises, something like loud hisses followed by loud snores. And when at last one of the old birds returns with a mouse in its talons the outcry grows louder than ever.