Human negativity toward arthropods has been well documented but the factors that contribute to this negativity have been elusive. This study explored knowledge of arthropod carnivory and herbivory as possible casual factors that contribute to the negative tendencies preservice elementary teachers have toward most arthropods. Specifically, this study investigated the effect knowledge of arthropod carnivory and herbivory had on United States kindergarten through sixth grade preservice elementary teacher attitude toward that arthropod and belief concerning the likelihood of incorporating information about that specific arthropod into their future science classroom. A cluster randomized design with a control group was used for the study. The treatment group consisted of 147 preservice elementary teachers and the control group consisted of 151. Unique to this study is the finding that arthropod carnivory and herbivory are causal factors that strongly affect preservice elementary teacher attitude and belief toward arthropods. When the participants of the study were made aware that an arthropod they thought was a herbivore was actually a carnivore, their attitude and likelihood of incorporation significantly declined. When the participants of the study were made aware that an arthropod they thought was a carnivore was actually a herbivore, their attitude and likelihood of incorporation significantly increased. Implications and future research are discussed.