Abstract
The social spider Anelosimus eximius has evolved advanced subsocial behavior which increases the efficiency of web construction, the capture of large prey, and defense. Colonies were observed in the field and in the laboratory. Communication between colony members is effected by apparently tactile signals. Cannibalism usually follows a breakdown in the communication mechanism and most frequently involved juveniles preying on sick or dead adults, and also on broodmates. Since cannibalism on nonfunctional and redundant colony members conserves energy, this trait may have been maintained by selection and should not necessarily be considered primitive. <br /><br />
