According to the story, pirate perch are solitary and nocturnal, making them very hard to study. But a few researchers managed to get their hands on some. Using mesh bags and trash cans, they placed the perch and several other predator species in areas where frogs and beetles lay their eggs. In the areas where other predators were placed, the frogs and beetles felt threatened and, therefore, did not lay any eggs. Oddly, the frogs and beetles where the pirate perch were placed laid plenty of eggs and could have cared less that the perch were present. This tells researchers that the perch must have a cloaking device, but here's the twist: There are both visual (camouflage) and olfactory (scent masking) forms of cloaking in the animal world, and the pirate perch isn't using either of those.