The filaments catch in the least projections on a prey insect's body or limbs. The web also is springy, and whether perching on the sheet or awaiting prey in its retreat, the spider reacts immediately to vibrations, whether from a courting male, the threatening struggles of dangerous invaders, or the weaker struggles of potential meals. They attack promising prey by rushing out at high speed and dealing a paralysing venomous bite. Once the prey has been disabled, the spider generally drags it back into the retreat and begins to feed. This method of attack is consistent with the high speeds at which Agelenidae run. Other sheet web hunters such as some Pisauridae also are very fast runners. Like any fast-running spider, the Agelenidae possess good vision, and are generally photosensitive (i.e. react to changes in the light), so they can successfully retreat upon perceiving a larger threat's shadow approaching. Some are also sensitive to wind blows, and can retreat before the prey even spots them. Males are less successful ambushers than females, so prefer to roam around and wander to new areas, rather than stay in one single web the whole time. In September, males of outdoors species (such as "Agelenopsis" and "Agelena") can seek refuge within houses, usually nesting on or underneath outer windowsills, or also around the porch door. These spiders often are neither pest controllers nor pests themselves; they are very selective in their prey, and do not consume large quantities; also, they are immune to intimidation and come back to their webs even after being disturbed, unless they are completely destroyed. The type genus, "Agelena", includes some parasocial spiders that live in complex communal webs in Africa. The best known of these is probably "A. consociata". Social behaviour in these spiders comprises communal web-building, cooperative prey capture, and communal rearing of young. However, no trophallaxis occurs, nor any true eusociality such as occurs in the social Hymenoptera (ants, bees, and wasps); for example, the spiders have no castes such as sterile workers or soldiers, and all females are reproductive. Only one species of agelenid has become prominent as a putative cause of a significant frequency of necrotic arachnidism; this is the hobo spider, "Eratigena agrestis". This perception arose when the species was accidentally introduced to the United States in the mid-20th century and propagated rapidly in several regions.