It is probably that very few of you, if any, ever saw a fish's nest; but there certainly are such things.
The fish which builds them is called the Stickleback. It is a little fish, but it knows how to make a good nest. The male stickleback is the builder, and when he thinks of making a nest he commences by burrowing a hole in the mud at the bottom of the stream where he lives. When with his nose and body he has made this hole large enough, he collects bits of grass, roots, and weeds, and builds his nest over this hole, which seems to be dug for the purpose of giving security to the structure. The grass and other materials are fastened to the mud and earth by means of a sticky substance, which exudes from the body of the fish, and every part of the nest is stuck together and interlaced so that it will not be disturbed by the currents. There are generally two openings to this nest, which is something like a lady's muff, although, of course, it is by no means so smooth and regular. The fish can generally stick its head out of one end, and its tail out of the other.
When the eggs have been laid in the nest, and the young sticklebacks have been born, the male fish is said to be very strict and particular in the government of his children. For some time—while they are yet very small—(and the father himself is a very little fellow) he makes them stay in the nest, and if any of them come swimming out, he drives them back again, and forces them to stay at home until they are of a proper age to swim about by themselves.
We have now seen quite a variety of nests, and I think that we may come to this conclusion about their builders:—The bird or other creature which can carefully select the materials for the home of its young, can decide what is most suitable for the rough outside and what will be soft and nice for the inner lining, and can choose a position for its nest where the peculiar wants and habits of its little ones can be best provided for, must certainly be credited with a degree of intelligence which is something more than what is generally suggested by the term instinct.
