1. Attracting mates: Many animals, especially insects, use pheromones to signal their sexual availability to potential partners. This can include attracting mates from a distance, triggering courtship behaviors, or even indicating the animal's reproductive readiness.

2. Marking territory: Some animals use pheromones to establish and defend their territory. These scent signals can communicate ownership to other animals, deterring intruders and potential rivals. This is particularly important for animals that are solitary or have a specific home range they defend.