They frequently build their webs in woodpiles and sheds, closets, garages, and other places that are dry and generally undisturbed.

[6] Infestations have been reported in the United States (Massachusetts, Florida, Kansas[7]), Canada (Vancouver, British Columbia),[citation needed] and Australia.

[8][9] Local daycares, preschools and schools arrange daytrips here and parents are forewarned about the risk by required consent forms, although only one bite has ever been recorded.

[10] As indicated by its name (laeta meaning "happy"), this spider is not aggressive and usually bites only when pressed against human skin, such as when putting on an article of clothing.

Like all sicariid spiders, the venom of the Chilean recluse contains the dermonecrotic agent Sphingomyelinase D, which is otherwise found only in a few pathogenic bacteria.

Initially there may be no pain from a bite, but over time the wound may grow to as large as 10 inches (25 cm) in extreme cases.

Bites are felt initially but may take up to seven hours to cause visible damage; more serious systemic effects may occur before this time, as venom of any kind spreads throughout the body in minutes.

Viscerocutaneous loxoscelism manifests with skin blanching due to vasoconstriction, sometimes a dengue-like scarlatiniform rash, hemolysis, sometimes resulting in hemoglobinuria, hemolytic anemia and acute tubular necrosis leading to kidney failure, and death in 3%–4% of cases per a study covering 30 years of bites in Chile.

Of the 47 who had viscerocutaneous loxoscelism, 9 died, representing a mortality rate of 19.1%, 6 were women and 3 were men, aged 2 to 37 years, 6 occurred in the summer, two in the fall and one in the winter.