The Fatal Eggs the pre-plague level. However, the chicken eggs which are imported from outside the country are, by a mistake, sent to Persikov's laboratory while the reptile eggs destined for the professor end up in the hands of the farmers. As a result, Rokk breeds an enormous quantity of large and overly aggressive snakes, ostriches, and crocodiles which start attacking people. In the panic that follows, Persikov is killed by a mob — which blames him for the appearance of the snakes — and his cameras are smashed. The Red Army attempts to hold the snakes back, but only the coming of
Bird hens, lay eggs even when not fertilised, though unfertilised eggs do not produce offspring. Many species of birds are economically important as food for human consumption and raw material in manufacturing, with domesticated and undomesticated birds (poultry and game) being important sources of eggs, meat, and feathers. Songbirds, parrots, and other species are popular as pets. Guano (bird excrement) is harvested for use as a fertiliser. Birds prominently figure throughout human culture. About 120–130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Human activity threatens about 1,200 bird species with extinction,