Vibrating Spiders – Family Pholcidae
These spiders probably prey upon each other when the pickings get slim in the wintertime, but as of September, there are still enough flying insects visiting for all to coexist peacefully.
These spiders, when threatened, “vibrate” their legs and bodies so rapidly as to become invisible; hence their other common name: vibrating spider. Actually, what they do is spin themselves in a small circle – it’s really quite a sight!
There is an old wives’ tale about this family of spiders, viz. that their bite is the most dangerous, or their venom is the most lethal known to man.
These spiders have not the equipment for delivery of any but the tiniest amounts of venom, and that dangerous only to the smallest of creatures, flies and other spiders, etc.
I found this specimen living in close proximity to Steatoda cobweb spiders in my garage.
1. Authors: H.V. Weems, Jr., and G.B. Edwards, Jr., Florida Dept. of Ag, Entomology Circular 193.
Tree Encyclopedia / North American Insects & Spiders