Permission to Bite: White-footed mice show no increased grooming response to tick infestation

The presence of parasites can significantly influence animal behavior. Specifically, grooming behavior may have evolved as a direct response to parasitism. This adaptation, observed in a wide range of species, serves as a direct response to the physical and psychological challenges induced by parasite infestation. Grooming behaviors, which can be individual or social, help remove parasites, maintain hygiene, and offer stress relief. These interactions underscore the adaptive coping strategies of animals for environmental challenges, highlighting the role of parasites in shaping animal behavior and survival. A continual rise in human cases of vector-borne disease demands a more detailed understanding of how ticks interact with their host species that usually serve as pathogen reservoirs. White-footed mice (Peromyscus leucopus) are one of the most frequently studied hosts of blacklegged ticks (Ixodes scapularis); however, how this species interacts with ticks in the field is poorly understood. This study aimed to quantify activity patterns in white-footed mice and to assess their behavioral responses to parasitism by blacklegged ticks within a controlled setting using Ethovision® software. White-footed mice were infested with nymphal blacklegged ticks or evaluated without tick infestation over 4 days. The mean number of ticks on the mice after the infestation period was 19.6 ± 5.9, and the mean number of ticks that attached and fed through the duration of the trial on the infested mice out of these was 8.6 ± 4.4. Grooming frequency was not significantly affected by tick parasitism, regardless of the number of attached ticks. While this study was the first to quantify behavior on lab-reared white-footed mice in response to blacklegged tick parasitism, further work is needed to determine how wild-caught white-footed mouse behavior might differ.