Arthrobotrys flagrans is a fungus that acts as a natural pest controller by trapping and killing parasitic nematodes that damage crops and livestock. Scientists studied three key genes in this fungus that contain CFEM protein domains and found they are critical for forming sticky traps and controlling how deadly the fungus is to nematodes. The research shows that when certain CFEM genes are removed, the fungus produces stickier traps and kills more nematodes, while removing other CFEM genes has the opposite effect, providing insights for developing better biocontrol products.