Brown Recluse bites are actually incredibly rare, even in areas where the brown recluse is known to inhabit. This article presents one of the reasons why, brown recluses do not usually occur singly, one usually finds dozens of these spiders. If your home isn't crawling with them, you probably didn't get bit by one.
They are fairly shy spiders, it is difficult, even with provocation, to convince them to bite.
Also, they are fairly small. The majority of recluse spiders are not large enough to cause envenomation.
Most scientists who work with recluses are of the opinion that the vast majority of "recluse bites" are caused by a number of other factors including insect stings and bites, infections, tick bites, and a myriad of necrotic conditions.
Finally, recluses would not be found in Calgary.
