A parasite makes rats stop being afraid of cats — on purpose

Toxoplasma gondii can only complete its life cycle by reproducing inside a cat's gut, so it needs an infected rodent to get eaten. Studies show infected rats and mice lose their instinctive aversion to cat scent, sometimes even seeming drawn to it, making that fatal encounter far more likely.

— Wendy M. Ingram et al., Mice Infected with Low-Virulence Strains of Toxoplasma gondii Lose Their Innate Aversion to Cat Urine — PLOS ONE, 2013