4.1. Experimental Animals

All experimental (behavioral) procedures are in compliance with the Guide for the Car and Use of Laboratory Animals published by the National Institutes of Health, Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 and in accordance to guidelines of our University. For the experiments the terrestrial snails Helix lucorum (Gastropoda, Pulmonata), were used. The capture of animals in the wild were carried out by competent persons without avoidable pain and distress (Article 9 of Directive 2010/63/EU). Snails transported asleep and then most of them were also stored asleep (Article 33 of Directive 2010/63/EU). Prior to the experiments the snails were kept for no less than two weeks in a glass terrarium in a humid atmosphere at room temperature (each group in a separate terrarium) (Article 33 of Directive 2010/63/EU). All groups were housed in separate terrariums which were kept together all the time in the same room under the same conditions. After behavioral experiments snails were outputted again into the terrarium. Snails were kept in the active state for at least 2 weeks before experiments with the possibility of free movement. Snails of approximately the same weight (about 25 g) were selected for experiments. The animals were deprived of food for three days prior to the experimental sessions.