There are many species of arthropods in the Czech Republic and Slovakia that suck blood in humans and cause unpleasant skin reactions. The extent and type of local reaction depends on the number of previous exposures to the given ectoparasite species, which is also related to possible therapeutic interventions. The review summarizes the classes of arthropods that suck blood in humans in the Czech Republic and Slovakia. The most important families of ticks (Ixodidae) and mosquitoes (Culicidae) pose the risk of transmitting the infection to humans. The individual infectious diseases, especially the possibilities of diagnosis and treatment of stages not requiring hospital care, and the most common myths related to this issue are briefly described.