Most bites are not venomous, but only irritating. There are, of course, exceptions. A relative newcomer in North America is the hobo spider, which hitched a ride from Europe on a ship that docked in Seattle around 1930. Hobo has since spread to several states in the Northwest. Some others can cause significant discomfort, like the tarantula, which to many appears ugly enough to be fatal, but isn't.
Tarantulas eat scorpions, by the way, which can be far more harmful.
Fatalities from spider bites are extremely rare, and treatments are readily available in the geographical areas where the spiders are found. So spiders are not all that dangerous, and they provide valuable service to our environment. They should be loved, not loathed, Rayor says. Of course, she was destined to believe that almost from the beginning. As a graduate student at the University of Kansas, she turned up one day with a box full of spiders and showed them to her fellow students of entomology.