(Amaurobius ferox)
Amaurobius ferox, sometimes known as the black lace-weaver, is a common nocturnal spider belonging to the family Amaurobiidae and genus Amaurobius. Its genus includes the permanently social species A. socialis, and three subsocial species, A. fenestralis, A. similis and A. ferox, all three of which have highly developed subsocial organizations. Females of this species range from around 11–16 mm in body length, while males are slightly smaller and more slender, ranging from 8–10 mm.The spider is very dark in color with its primary shades being black, brown, dark red, and tan. The abdomen is rounded and has light yellow pale markings in a unique pattern that is often described as resembling a ghoulish mask or skull pattern. A. ferox is usually found near man-made structures. The species prefers dark areas, such as underneath logs or inside cellars, and it often likes to live in moist, shaded crevices including underneath stones or dilapidated walls. In the spring, adult males can likely be found indoors while they wander in search of mates, but adult females can be found indoors or outdoors at any time of the year. A. ferox is native to Europe and is distributed across the continent, but it has been introduced into all three countries of North America, as well as New Zealand and some Eastern European countries such as Turkey. The spider is extremely rare in Northern Europe where temperatures are too low for its survival.