Question: Generally speaking are all spiders venomous, and therefore poisonous?

Answer:

Well, yes and no.  Doublespeak perhaps, but since I’m a geek and like to be technically correct (Summer begins in June, not on Memorial day!) I will indulge in a bit of verbal hairsplitting.  With the exception of just a few species, spiders use venom to subdue their prey.  Venoms are toxins (poisons) to be sure used by spiders and many different animals (including some mammals).  What makes venoms unique as opposed to the passive defenses of say a poisonous frog are how they are delivered to the prey or intruder which is by some type of injection. Fangs, stingers, and spines are the tools most often used.

So, if spiders use venoms, how then could they not be called poisonous? I’ll again use my cats to illustrate.  On many occasions I’ve seen the kitties poking at something in the basement and upon investigation noticed that it was some type of hunting spider that had wandered in.  Often times the spider becomes a quick snack before I get a chance to remove it, and the cats have had no ill effects whatsoever.  In fact, spiders as food are considered a delicacy in some cultures around the world!  I’ll pass thanks.

Even if the reality is that only a handful of species in the US and maybe two dozen worldwide are ‘medically important’ that does not discount the fact that for many of you, spiders are creepy, and not welcome houseguests.  For spider management, call the pros at Colonial Pest.