A spider web is a device built by a spider out of spider silk extruded from its spinnerets. Insects are trapped in spider webs, providing nutrition to the spider. (Only about half of all spiders spin webs to catch prey. Others simply stalk their prey.) The spider, after spinning its web, will then wait on, or near, the web for a prey animal to become trapped. The spider senses the impact and struggle of a prey animal by vibrations transmitted along the web lines.
Spiders do not usually adhere to their own webs. However, they are not immune to their own glue. Some of the strands of the web are sticky, and others are not. For example, if a spider has chosen to wait along the outer edges of its web, it may spin a non-sticky prey or signal line to the web hub to monitor web movement. Spiders have to be careful to only climb on the non-sticky strands of their webs. A spider positioned in the middle of the web makes for a highly visible prey for birds and other predators, even without web decorations. Many day-hunting orb-web spinners reduce this risk by hiding at the edge of the web with one foot on a signal line from the hub, or by appearing to be inedible or unappetizing.
Spider web tattoos have a dark history going back some seventy years, when Aryan or White Supremacy gangs reportedly wore the spider web tattoo as a form of racist braggadocio, reportedly a sign that they had terminated a visible minority. The spider web became de rigueur in prisons, with each ring of the web representing time spent inside, or how many prey' have been ensnared in the wearer's web. You might spot one on an elbow, sometimes on the back, or on the side of the neck, emerging from behind the ear, and more rarely, on the face. It has served as a billboard that the wearer is in for murder or as a warning to enemies to keep their distance -- especially one worn on the left elbow -- which advertises the web-wearer as one who has a deadly weapon tucked away. In the Russian prison system, where an elaborate language of tattoo designs and symbols has evolved, the spider web is often tattooed between the thumb and index finger. A web with resident spider is a confession to drug addiction. Sans spider means the wearer is a thief. On the neck, the spider web is a sign of repeated prison terms and solitary confinement for breaking prison rules.
Spider tattoos symbolize struggle -- struggling in the web of life'. Depending on your interpretation, this can mean struggle and capture in an illegal sense or simple the everyday trials and tribulations of life.