Сhromosomal machinery of highly excited animals with low threshold of the nervous system excitability (LT strain) is more susceptible to the damaging effect of high frequency EMR compared against the animals with high threshold of the nervous system excitability (HT strain). High nervous system excitability determines greater decrease in chromosome aberrations level in the presence of additional reflecting elements - Aires Defender Pro resonators under UHF-waves of standard Wi-Fi router. It is shown that the genotype of animals and the functional state of their nervous system affect susceptibility to the UHF EMR and the action of resonators.