Kaylee’s research focused on intersexual selection and female mate choice in members of the feather mite genus Trouessartia spp. (Analgoidea: Trouessartiidae). Such selection may promote the divergence of genital morphologies among species. Previous studies on other arthropods have shown that strong phylogenetic correlations exist between changes in the morphology of female internal genitalia and the male intromittent organ. The genus Trouessartia is of particular interest as the female spermaduct (sperm-transmitting tube) ranges from being located entirely within the body to extending externally for considerable lengths. Using a molecular phylogeny of the host birds as a proxy for the mite phylogeny, she tested whether coevolutionary relationships exist between male and female genitalia. One of the patterns she found is that in species where females have relatively long external spermaducts, males have comparatively massive genitalia.