Entomology is a branch of zoology that focuses on the study of insects. Insects are a diverse group of animals that belong to the class Insecta. They have six legs, a segmented body, and usually a pair of wings. Entomologists study various aspects of insects, including their biology, ecology, behavior, taxonomy, and evolution. They observe and analyze insect species, their habitats, life cycles, feeding patterns, and interactions with other organisms. By studying insects, entomologists contribute to our understanding of the natural world and the role insects play in ecosystems. They also play a crucial role in pest management and conservation efforts. Therefore, option 2, Insects, is the correct answer.