Chemical mimicry of an organism's pheromones allows predators with this ability to draw select prey to them, rather than spend their energy finding and attempting to capture these organisms with varied success. The pheromones are typically used by the prey species to attract members of their own species as potential mates. In the case of predatory chemical mimicry, the predator has evolved to emit chemicals that are structurally similar and will cause the same behavioural reactions to be displayed by the prey. However, the mimicked pheromones will draw the animal toward the predator rather than a potential mate.
One group of organisms that use this method are Bolas spiders (genus: Mastophora). Bolas spiders emit chemicals that attract their prey, noctuid moths. These spiders have replaced the need to spin elaborate webs to capture prey by mimicking the pheromones emitted by female moths to attract males of the species effectively. In studies conducted on this spider it has been found that the moths only approach from downwind of the spider and that all of the moths captured were, in fact, male.