Parasites that steer nocturnal hosts into water do not rely on lunar cycles, study finds

Like many parasites, nematomorphs are known to manipulate their hosts' behavior to complete their life cycles. Also known as horsehair worms, among other names, these creatures develop in their hosts' body cavities and lure their terrestrial arthropod victims into the water, where the parasites reproduce. Some species have even been observed to induce positive phototaxis, attracting the host toward horizontally polarized light reflected on the water's surface.