Which of the following is used to attract insects?

Pheromones are chemical substances produced and released by organisms that influence the behavior of other individuals of the same species. In the context of pest management, pheromones are commonly used to attract insects, particularly for purposes like trapping or monitoring pest populations. This attraction is based on the insects' natural behaviors, which may involve seeking out mates, food, or specific hosts.

Predacides, repellents, and miticides serve different functions. Predacides are designed to target predatory organisms, repellents are chemical substances that deter insects from approaching or feeding, and miticides are specifically formulated to control mites. Therefore, none of these options is meant to attract insects, making pheromones the only correct answer for attracting them in pest control practices.