Some fungi are actually carnivorous. Stephenson notes that nematode-trapping fungi use a variety of devices to capture their prey and extra nitrogen from them, from sticky secretions to adhesive nets. The latter is depicted in this image, where the fungus Arthrobotrys oligospora has netted a nematode (also known as a roundworm). "There have been some attempts at commercial applications of these guys," Stephenson says. "Plant nematodes are major agricultural pests, so if scientists can produce a fungus can help control them that's a good thing."