Up to the present time I have not yet attempted to make an artificial mouse, though I feel sure a good one will be found of great service to use in larger rivers and the edge of lakes. I have on several occasions taken the very young of musk-rats and water-rats in fresh condition from the stomachs of brown trout, bass, and chub. In some localities the natural mouse or young rat is a favorite bait for pike, also muskellunge will take them of larger size. Many young musk-rats are doubtless taken by fish while the young creatures have been crossing the stream, which they often do, following after their parents in search of food. A good artificial requires to have movable forelegs to swim half submerged. The angler who is provided with a set of these baits, live or artificial, is fully equipped to fish for any species of game-fish, in any season or condition whatever.
Before concluding this chapter, mention should be made of why I have not included the large family of Coleoptera, or water-beetles, so very abundant in lakes, ponds, and slow-moving streams. In many examinations of stomach contents of various game-fish, I have not yet found evidence that adult water-beetles furnish enough of the food-supply to make it necessary for artificial imitations. Leonard West, in his admirable book, The Trout-Fly, gives several varieties that trout feed on, and even prefer to insects. Those he mentions must be habitants of deep, slow-moving streams. Many varieties of beetle creepers do certainly furnish considerable bottom food for trout, because their habit is not to hide, but to move about among the pebbles in search of food during the daytime. Many of the adult water-beetles toward evening leave the streams and spread their wings to soar in the air. In the early morning they again seek their watery homes. There are several beetles pictured in Trout Stream Insects, one, in particular, for May, called the red bug, of which the artificial is a most taking fly for trout. Another, somewhat smaller, called the red-headed gnat, is quite as effective for hot-day fishing. Both are abundant on the water during May and June, though not bred in the water, being land-beetles. The subject is one in which I hope to make further studies. This chapter on "the relative value of baits," would be incomplete without reference to the garden and night-walker earthworms as trout food, though strictly speaking they are not natural fish food, as they are found most abundant away from water. It is rather from centuries-old associations as to their use as trout baits that they are mentioned here as having been - up to the present time - almost universally used by every trout angler, young and old, from the time of Izaak Walton. Their continued wriggle in the water after being impaled on the hook is what attracts trout. It would be idle talk - nay, false - to say that the earthworm is unattractive, yet I can say, after long and earnest practice of its use, also from the study of many books written about it - in particular the work of W. C. Stewart, the Scotch expert - in very truth that the earthworm is not really so effective as it is supposed or said to be.
The worm is of greatest service when the water is colored, and in flood and just after a flood. Its greatest danger and harmfulness is when being used as a bait to float down a small brook to attract and capture large quantities of undersized fingerling trout. Sometimes, at early season, before insects are abundant on fair-sized running streams, worms will attract the brook-trout, less often the brown trout, but rarely the rainbow. If sunk to the bottom of deep pools, a kicking worm will entice large fish; not always, however; certainly less often than if the artificial fly is skilfully played in the same spot.
Under normal conditions of water, season, and weather, should two anglers go together downstream - on one side the worm-fisher, on the other a fly-fisher; the latter will, if fairly skilful, always bag the fullest creel. I have proved this many times, and the reason is obvious: Insects are the natural food of trout; worms are not. We would never dream of digging for worms alongside a river, but go directly to the nearest corn or potato patch, or, better still, a garden or dunghill where they abundantly abide and breed.
It is a regrettable thing to have writers and sporting magazine editors constantly lauding the worm as a trout bait. Such writers are either incompetent fly-fishermen or they write from hearsay and traditional imagination of abnormal conditions. In general use, a well-chosen and properly played fly, either sunk or at the surface, is almost certain at any season, time, or place to attract . trout better than worms, except, as previously stated, when fishing brooks for fingerlings.