I did not expect to read the phrase "males have terminal nuptial gift sacs on their penises" today but here we are
A delightful paper comparing mating behaviour across _Leiobunum_ harvester species which have, or lack, nuptial gift-giving, out of Mercedes Burns' lab at the University of Maryland Baltimore County: https://doi.org/10.1016/j.anbehav.2025.123150 
