infested
A normal giant gliding ant (left) and an infested ant (right). The red color of the gaster is not caused by a pigment, but thinning of the exoskeleton combined with the color of the nematode eggs. From Yanoviak et al, 2008.
In one of my favorite episodes of the animated TV show Futurama, the chief protagonist - delivery boy Philip J. Fry - becomes infested with worms after eating a dodgy egg-salad sandwich purchased from the restroom of an interstellar truck stop. Lucky for Fry, the parasites are beneficial - they repair his injuries and greatly enhance his cognitive abilities. ("Of all…