copulation as a means of arousing the resident female. These signals involve the male using his forelegs to "pull" or "pluck" a segment of silk he previously threaded into the signal strand on the female's web. The third, "burping" signal is produced by the male as he approaches the female in her retreat, and is likely used to warn the female that he is a potential mate, and not prey. This "burping" practice prevents the female from attacking the male as he begins engaging in the "pulling" and "plucking" pre-courtship signaling. The temporal patterning of these vibrational courtship signals enable the female to distinguish between a potential mate and potential prey items in her web. Social behavior Zygiella x-notata is a species of solitary orb-weaving spiders. Apart from mating and spiderling kin-related sociality prior to dispersal, adult Z. x-notata do not interact socially with other individuals of the same species. However, the close proximity in which webs are built in their natural environments (i.e. near or on human constructions) may lead to aggressive, territorial behavior between individuals. Within species aggression With a growing human population, many Zygiella x-notata have adapted to living on or near human constructions in urban, suburban, and rural areas. Urban environments provide orb web building spiders, such as Zygiella x-notata, with sufficient locations in which to build their webs. However, high quality web building sites are coveted by many individuals of both the Zygiella species and other web-spinning species. In an urbanized environment, Zygiella x-notata exhibit high within-species aggression. This is in part due to the favorability of diverse, but stable, aggressiveness types in urban dwelling spiders. Aggressiveness may facilitate high density aggregations of spiders. Aggregations have been observed to consist of up to 25 individual spiders per square meter. However, high aggression rates within a population could prove costly. Increased aggression results in higher incidences of injury and death due to greater inter-individual fighting. Consequently, this aggressive typology is constrained to urban dwelling Zygiella found in web aggregations near preferential habitual spaces, indicating evolving behavioral plasticity in the species. Predators Wasps Wasps are active predators of spiders, particularly engaging in predation behaviors during the spiders' reproductive period. Wasp attacks by the species Vespula germanica are common in Zygiella x-notata. Male spiders and smaller females are at greater risk of predation by wasps. Male preference Males are located for predation by wasps more frequently than females.