Scientists at VIB and Vrije Universiteit Brussel have made a significant discovery regarding the biopesticide Bacillus thuringiensis (Bt), known for its eco-friendly pest control capabilities. Their study, published in *Nature Communications*, identifies a previously unknown mechanism involving a fibrous network termed 'sporesilk.' This network traps infectious spores and toxins, forming compact 'infection units' that enhance the bacterium's ability to kill insect larvae effectively. Bacillus thuringiensis operates by releasing toxins that damage the digestive systems of targeted insects, allowing spores to germinate and multiply within them. The researchers found that the sporesilk, consisting of ultra-strong protein fibers only eight nanometers wide, provides stability and resilience under extreme environmental conditions. By genetically engineering or adding purified sporesilk fibers, the researchers were able to significantly improve the clustering of spores and toxins, thereby increasing the biopesticide's effectiveness. This advancement not only promises to enhance biopesticide potency but also highlights the potential for creating new biomaterials in biotechnology and engineering, contributing to sustainable agricultural practices.