KLEPTOPARASITISM - What the heck is that!?

Kleptoparasitism

Kleptoparasitism describes the behaviour of a few different genera of spiders that steal the food from other spiders.  The most obvious example one is likely to come across is the tiny Dew-Drop Spider (Argyrodes spp) feeding off the discarded prey remains of the massive Golden Orb Web Spider (Nephila spp).  Some species will even feed on the web itself for added protein. 

 Above: Argyrodes sp. (Family Theridiidae) - DEW DROP SPIDER.  These tiny spiders often live in the webs of a much larger Nephila sp. (Family Nephilidae) Golden Orb Web Spider, living off of the discarded remains of old prey.  I personally watched this particular individual actively steal fresh prey from the larger spider when the larger spider was distracted (another fly was caught in the web elsewhere).
Dew Drop Spiders come in all sorts of funny shapes, with large bulbous abdomens, as shown here, or long protruding ones.

 Above: Nephila fenestrata - BLACK LEGGED NEPHILA (Golden Orb Web Spider), whose massive web harboured at least 3 Kleptoparasitic Dew Drop Spiders.