CCK and infection: Mice became hypophagic from days 6–10 post infection (p.i.), during the transient period of T. spiralis induced enteritis, and we observed a significant increase in CCK positive I-cells in wild-types (Fig. 1C and E) mirroring hypophagia at days 6 and 9 p.i. Feeding then returned to baseline levels until undergoing a second period of hypophagia from day 18–19 p.i. The secondary period of hypophagia occurs during the period of muscle invasion and peripheral myositis, caused when larvae form the “nurse cell” in which the parasite resides.