Flowers produce nutrients, mainly pollen and nectar eaten by many animals. Insects searching for pollen and nectar transfer accidentally the pollen onto the stigma in another flower, cross-pollinating. In Poland, insects are the most numerous pollinating group of animals due to climatic conditions. The author presents coleopterons, dipterans, butterflies and hymenopterans, including bees. The structure of flowers and luring signals (colour and smell) are also dealt with.