Most spiders produce silk draglines and excreta as they move through the environment.
Through a number of studies, arachnologists know that male spiders can detect pheromones bound up in the silk of females. In this way, draglines are often a communication medium by which females advertise their willingness to mate and males will then follow this silk trail to the female for mating purposes. Spiders are capable of detecting chemical cues produced by insect prey . Further, wolf spiders, like Hogna helluo shown at the left, appear to be preferentially attracted to the chemical cues from whatever prey they were feeding on last. This means that the predator's recent diet may be a direct indicator of the level of predation risk.