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Active foragers Myrmica rubra were trained in a maze under conditions of different levels of colony need in food with carbohydrate (sugar syrup) or protein (ants Lasius niger pupae) reinforcement. Acquisition of the maze habit was better under conditions of reinforcement with pupae, especially by its time indices. Ants were able to modify the acquired habit when the reinforcement quality was changed. It was shown that learning was possible only when the colony and after a change pupae for the syrup was "hungry". Under these conditions, after a change of the syrup for pupae or visa versa the previously acquired optimum habit was transferred. Several hours later, with satiation of the colony, food reactions learned with protein reinforcement switched-over to "stochastic" non-optimized behavior with the dominance of exploratory reactions. Thus, it was shown that higher social insects ants were capable for conditioned switching-over. Different forms of this phenomenon depended on the level of the colony need in food and, consequently, on the level of the social food motivation of foragers ants.

It was shown that scout ants Myrmica rubra are capable for an adequate modification of foraging habit acquired in a multichoice symmetrical maze following a reward change (syrup for the species brood). Under conditions of the high level of food motivation of a family both during learning and "examination" (i.e., brood transportation) all the ants succeed in a conditioned switchover of heterogeneous reflexes. If the high level of motivation during learnings is changed for its low level during examination, some ant do not realize the new task. The unconditioned switch (preliminary 1-3 brood takes at the start ares) facilitates the successful performance. In different experimental sessions a certain ratio was revealed between the ants realizing different ways of correct decision making. Specially developed criteria made it possible to identify different individual types of behavior during examination: transfer of acquired strategy, its gradual adaptation, and fast switchover to the new strategy. The adequate maze method and learning on the basis of specific forms of social behavior of ants (foraging, brood transportation, and exploratory activity) promote the rapid and efficient acquisition of the habit and its modification.

Learning of ants was studied in a symmetrical multi-choice maze at different levels of food "social" motivation. A capability was shown of scout ants Myrmica rubra for changing rapidly behavioral strategy when the motivation level of a family changed from the low one for the high or vice versa. In the satiated state the ants demonstrated a clear-cut research activity. This activity was associated with high variability and instability of the maze habit. In the "hungry" state movement trajectories were rapidly minimized, the majority of ants used one dominant scheme of moving. Initial level of motivation determined the peculiarities of and learning and ability to transform behavioral strategies.

Ability was shown of ants Myrmica rubra to multiple reconstructions of the habit elaborated in symmetrical multialternative maze under motivation of care for the progeny (transportation of breed of the own species). Reconstruction consisted in the change of reinforcement location on the left or right aim spot. The ants showed the ability to carry out the series of eight reconstructions during one-two days. An improvement took place of the fulfillment of the last reconstructions in comparison with the first ones. Peculiarities of learning and reconstructions were found in two groups of animals differing by conditions of learning: at reinforcement on both ain spors or on one of them. The results obtained are considered as indices of high plasticity of the behaviour of ants of the studied species.

Behaviour of Gammarus oceanicus was studied in the open field test. For the whole except (n = 204) spatial-motor asymmetry was found. It was manifested in significantly greater number of movements clockwise (to the right) than counterclockwise (to the left). Animals with significant asymmetry dominated, forming 93.5% of the except. The asymmetry was characterized by distinct right-sided direction. Motor activity and spatial-motor asymmetry at repeated tests in the main weakened; the changes in "right" and "left" animals were manifested differently. The essential factor which disturbed the behaviour of the animals in the open field test (including the asymmetry of movement direction) proved to be a toxicant (oil pollution) action.

Asymmetry in direction of motion was found in Myrmica rubra ants at their learning in a symmetrical multi-alternative maze in conditions of "social" alimentary motivation. It was manifested in the form of preferable stay in the right half of the maze and was significant by several parameters: total number of motions, approaches to "false" spots and right turns. Unequal degrees of spatial-motor asymmetry (individual and for the whole sample) was revealed by various parameters. Most clearly the right-sided spatial preference was seen in the insects which had more approaches to goal with reinforcement taking than "exploratory" approaches. It is suggested that the parameters of motion direction asymmetry in ants learning in the maze depend on the level of alimentary "social" motivation.

The ability was studied of Myrmica rubra ants to change the habit of passing through a multialternative symmetric labyrinth at motivation of the care for posterity. In exams the location of reinforcement was changed: in the first exam the progeny was carried from both aim places to those symmetric to them relatively to labyrinth cross axis; in the second exam the reinforcement was left on one aim place non-preferred during learning. The first exam was passed by 62.5% of ants, the second--by 87.5%. In the first exam such parameters were worse as the first correct decision, the mean number of movements in the cycle, the total number of correct cycles. At elaboration of new motor habits and increase and inversion were observed of the initial spatial-motor asymmetry. Individual variations in ants behaviour increased. The ants who failed to solve the task, showed pronounced signs of preneurotic state. The obtained results testify to a high plasticity of ants behaviour and their ability to modify their activity according to changes of experimental situation.