EN
A few decades have passed since most of studies on neophobia in rats were conducted. In the case of such fast-breeding animals this period of time could have led to substantial changes in rat’s physiological and behavioral functions. What is more, there are the inconsistencies in research findings with respect to comparisons between wild and laboratory rats, and within domesticated strains. The procedure was designed to isolate specific fear of novel food from generalized fear of a novel object (i.e. container). Rats accustomed to one type of food served in a specific location and in a familiar container were given a different type of food. Each test trial was preceded by food deprivation. The following variables were measured: feeding latency, pace of eating, number of approaches to container, number of times food was sampled for each trial. The amount of food consumed in each trial was weighed and also taken into account. Grooming time served as the measure of stress in rats in the experiment. The analysis of differences between groups showed that rats in all groups achieved comparable values in analyzed variables at the start of the experiment. However, certain differences between strains emerged during the course of the experiment. It turned out that wild rats consumed less amount of food than Brown Norway and Sprague-Dawley in a few trials, demonstrated greater eating latency than Brown Norway, and when novel food was introduced, their number of approaches to food container was higher than those of Long Evans. WWCPS rats demonstrated significantly more of grooming behavior in nearly all trials. The results of the experiment did not confirm the assertion of some authors that wild rats avoid eating unfamiliar foods. All groups demonstrated only a temporary decrease in the amount of food consumed, the magnitude of which was similar in all strains. No evidence of particularly low neophobia in albino rats was found. However, the behavioral symptoms indicated higher level of stress in wild rats compering to the other groups.