One group of Wistar rats were taught to consume 0.2% solution of saccharin up to stable preference of the latter to water. The aversion was established by means of an angle acceleration rotation. This was preceded by feeding the saccharin solution unfamiliar to the second group of rats. The aversion formed more obviously in the second group animals. The data obtained is discussed from the standpoint of sexual characteristics of the taste preference, defence behaviour, ecological specifics of interaction of males and females with ambient milieu.