One of the most common (and generally valid) stereotypes of the solitary lone wolf type of predator is a spider. In almost all species, spiders do not associate with each other except when mating, when two of them are on a dinner date (which usually does not end well for one of them), or when the babies hatch and exit the egg sac en masse.
Note I said "almost all species." Out of the 45,000 known spider species, approximately 25 of them involve social spiders.
Social spiders generally build huge, three-dimensional webs--sometimes 25 feet (7.6 m) long and 5 feet (1.5 m) wide--containing as many as 50,000 spiders. An insect or even larger creature blundering into such a web will find itself immediately overrun and covered, horror-movie style, by hordes of these little vampires injecting it with poison and otherwise plying their trade. An arachnophobe would probably find himself or herself highly stressed if tangled in one of these colonies.
Unlike the case with ants, bees, termites, and and other more conventional social insects, there is nothing to physically distinguish one spider in the web from another, although the percentage of females far exceeds that of the males. Nonetheless, each individual spider tends to specialize in a particular task, such as web repair, subjecting prey, housecleaning, removing parasites, or feeding the young of itself and others by vomiting regurgitated food into their mouths. This specialization occurs notwithstanding the fact that there is massive inbreeding within the colony and the spiders are genetically very similar. Scientists believe that the task assumed by a spider is largely determined by its early childhood experiences and its unique basic personality.
Evolution favors social spiders in areas of the world where there is heavy rainfall which would destroy flimsy individual webs, where potential prey is large and not easily subdued by a single spider, and where the spider species naturally makes a three-dimensional web, which is much easier to join with others in a colony as compared to the standard two-dimensional orb web.
For more information on these amazing arachnid associations, click here.
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