To be a predator of a social species such as ants or humans you must not raise alarm. A hoverfly, tricks ants into keeping their larvae. It grows to a monstrous size, discretely feeding on ant larvae. The ants are unable to see it as a threat. Larvae simply disappear.

With our excellent vision the deception is obvious. But, what is also obvious is that the creatures that take advantage of humans would be just as invisible.

Sometimes... people just go missing? Right?