The favorite food of prairie-dogs consists of the stems and roots of gramma grass and other richly nutritious forage plants. In addition they eat any native fruits, such as that of the pear-leaved cactus (_Opuntia_) and are extremely destructive to grain, alfalfa, and other cultivated crops. In addition to ordinary vegetation, they eat grasshoppers and are fond of flesh, sometimes being caught far from their homes in traps set for carnivores. They keep the grass and other vegetation cut down or entirely dug out over much of the “town” and especially in a circle about each entrance mound, apparently for the purpose of obtaining a clear view as a safeguard against the approach of any of their many four-footed enemies. This habit is exceedingly injurious to the cattle ranges and often results in much erosion of the fertile surface soil. [Illustration: PRAIRIE-DOG _Cynomys ludovicianius_] [Illustration: STRIPED GROUND SQUIRREL _Citellus tridecemlineatus_] The vast numbers of prairie-dogs over so large a part of the grazing areas of the West take a heavy toll from the forage and other crops. As a consequence a campaign of destruction is being waged against them as the country becomes more and more settled, and they will eventually disappear from much of their present range. However detrimental they may be from an economic point of view, they are among our most interesting species, and when taken young their playful disposition and intelligence render them most entertaining captives. [Illustration: CALIFORNIA GROUND SQUIRREL _Citellus beecheyi_] [Illustration: ANTELOPE CHIPMUNK _Ammospermophilus leucurus_] Owing to the constant danger to which they are subject from coyotes, foxes, bobcats, badgers, and black-footed ferrets, in addition to eagles and other birds of prey, prairie-dogs are constantly on the alert. At any suspicious occurrence the first to observe it runs to his entrance mound, if the danger is not pressing, but otherwise to the nearest mound, where he sits up at his full height, “barking” and vibrating his tail, ready, if necessary, to disappear instantly. At the same time the “town” is alive with scurrying figures of the habitants rushing panic-stricken for their homes, and the air is filled with a chorus of their little barking cries. When all have been frightened to cover barking continues in the burrows, but an hour or more may pass before a “dog” will reappear.