Various fungi are known to infect insects and alter their behavior, presumably to assist in spreading fungal spores as widely as possible. But little is known about how the fungi affect behavior. UC Berkeley scientists have now found a fungus that infects the common lab fly, Drosophila melanogaster, providing a model in which to explore behavior-manipulating fungi. They found that the fungus invades the nervous system first while slowly eating the fly’s fat and organs.