James Blish, The Seedling Stars, New York, The New American Library, (1957) 1959, p. 104-105.

A stone loomed ; Lavon surveyed it in the half-light. Almost immediately he saw what he had hoped to see : the sand-built house of a caddis-worm, clinging to the mountainous slopes of the rock. He waved in his special cadre and pointed.

Cautiously the men spread out in a U around the stone, the mouth of the U facing the same way as the opening of the worm’s masonry tube. A Noc came after them, drifting like a star-shell above the peak ; one of the Paras approached the door of the worm’s house , buzzing defiantly. Under cover of this challenge the men at the back of the U settled on the rock and began to creep forward. The house was three times as tall as they were ; the slimy black sand grains of which it was composed were as big as their heads.

There was a stir inside, and after a moment the ugly head of the worm peered out, weaving uncertainly at the buzzing Para which had disturbed it. The Para drew back, and the worm, in a kind of blind hunger, followed it . A sudden lunge brought it nearly halway out of its tube.

Lavon abouted. Instantly the worm was surrounded by a howling horde of two-legged demons, who beat and prodded it mercilessly with fists and clubs. Somehow it made a sound, a kind of bleat as unlikely as the bird-like whistle of a fish, and began to slide backwards into its home- but the rear guard had already broken in back there. It jerked forward again, lashing from side to side under the flogging.

Lavon sent five Didin after it. They could not kil lit, for it was far too huge to die under their poison, but they could sting it hard enough to keep it travelling. Otherwise, it would be almost sure to return to the rock to start a new house.

Lavon settled on an abutment and surveyed his prize with satisfaction. It was more than big enough to hold his entire clan- a great tubular hall, easily defended once the breach in the rear wall was rebuilt, and well out of the usual haunts of the Easters. The muck the caddis-worm has left behind would have to be cleaned up, guards posted, vents knocked out to keep the oxygene-poor water of the depths in motion inside.It was too bad that the amoebae could not be detailled to scavenge the place, but Lavon knew better than to issue suxh an order. The Fathers of the Protos could not be asked to do useful work ; that had been made very clear.