Technical Abstract: The influence of seed structure and strength on their destruction by granivores is central to understanding the dynamics of granivore-plant interactions. The effects of seed size (cm3), mass (mg), density (mg/cm3) and coat strength (MPa) on the damage inflicted to up to nine seed species were evaluated for three post-dispersal granivores (Harpalus pensylvanicus, Anisodactylus sanctaecrucis, and Gryllus pennsylvanicus). The proportion of seeds destroyed were evaluated under choice and no-choice conditions for the different seed predators, and the relative destruction rates for the seed species were correlated with their characteristics. Seed destruction rates by G. pennsylvanicus were entirely unhampered by the size and toughness of the seeds. Seed densities significantly affected their destruction by A. sanctaecrucis and H. pensylvanicus, as did seed size, mass, and strength in H. pensylvanicus under choice conditions. When significant, beetles destroyed more of the small, denser seeds with stronger seed coats than weaker seeds. The significance of these results, which disagree with some previous studies on the topic, is discussed. Finally, the destructive capabilities of these three granivores for the different seeds are finely distinguished, which suggests a way for diverse communities of post-dispersal granivores to share a single resource within a habitat.