HEALTH: Infected Ixodes ricinus ticks are attracted by electromagnetic radiation of 900 MHz Ticks and Tick-borne Diseases Abstract The electromagnetic field (EMF) is known to influence functions of the nervous, cardiovascular and reproductive systems of many animals, including ticks. The aim of this study was to test the behavior of ticks in the presence of radio-frequency EMF. For testing, 160 adult male and 140 adult female unfed Ixodes ricinus ticks were used. Individuals were exposed to 900 MHz EMF in the Radiation–Shielded Tube (RST). Ticks were attracted to the irradiated area. This effect was significantly stronger for ticks infected with Rickettsia spp., suggesting that pathogens can alter the ticks’ response to environmental stimuli. These results lead to the question of whether man-made EMF may have an impact on I. ricinus activity and, as such, be a contributing factor to the ongoing changes in the distribution of the tick and its pathogens currently observed in Europe and elsewhere. Conclusions In conclusion, we showed in experimental conditions that I. ricinus ticks sense EMF from artificial sources and that they express affinity toward the irradiated area. Interestingly, this effect was significantly stronger for ticks infected with Rickettsia spp., suggesting that these pathogens can alter tick host response to EMF. It is thus possible than man-made EMF can have an impact on I. ricinus questing activity and that it could be partly responsible for the dynamic changes in the activity. -Courtesy Dr. Amy