Argyrodes argentatus is a kleptoparasitic spider. In Singapore, it is often seen in webs of Nephila antipodiana. On Guam it can often be found hanging in webs of the much larger spider Argiope appensa: while A. appensa can reach a total length of about 7 cm, A. argentatus females reach only 3mm, and males 2mm at the most. Like in rats, following copulation the male seals the female's epigyne with a mating plug, preventing the female from further mating.