To help plants better fend off insect pests, researchers are considering arming them with stones.The University of Delaware’s Ivan Hiltpold and researchers from the Hawkesbury Institute for the Environment at Western Sydney University in Australia are examining the addition of silicon to the soil in which plants are grown to help strengthen plants against potential predators.The research was published recently in the journal Soil Biology and Biochemistry and was funded by Sugar Research Australia. Adam Frew, currently a postdoctoral research fellow at the Charles Sturt University in Australia, is the lead author on the paper.