[Correlation between genetic and environmental factors in the display of predatory reactions in the rat].

Manifestation of the hunting and mice-killing reactions by non-linear rats-observers did not depend on the presence of rats killing mice. The absence of such dependence was observed in conditions of free access to food, of food deprivation stimulating predatory aggressiveness, and also of learning in the early postnatal period. Acquisition of the habit of eating killed mice by the rats-observers was facilitated in the presence of rats executing this reaction. It is suggested that in manifestation of the aggressive component of predatory behaviour of rats, a greater role is played by inborn mechanisms while environmental factors are more significant for organization of the alimentary mechanism.