Black Widow Spider

Description - Adult female body legth about 1/2", abdomen almost spherical. Black with two reddish triangular markings usually joined to form a reddish hourglass-shaped marking on the abdomen.    
Habits - Commonly live among and under stones and pieces of wood, in hollow stumps and trees, rodent burrows, sometimes in shrubbery. Prefer dry man-made structures including barns, outhouses, sheds, meter boxes, brick veneer, barrels, woodpiles, foundations, etc. If they are found indoors they are in seldom used parts of garages, basements, and crawlspaces.    
Lifespan/Reproduction - Eggs are about 3/8-1/2" in diameter and can be constructed in 1-3 hours. Females can lay from 6 to 21 sacs in a lifetime with about 185-464 eggs per case. Incubation period ranges from 8 to 30 days. Take nearly a year to mature from egg to adult and females can live for approximately 2 years. Spin irregular webs and females generally avoid light and is normally shy and retiring.    
Problems Encountered - Females have venomous bites (a neurotoxin). Female will aggressively attack after egg laying and when guarding her eggs. Bites cause slight local swelling with 2 tiny red spots where the fangs entered. Pain is almost immediate and reaches its maximum in 1-3 hours continuing for 12-48 hours. May experience increased body temperature and blood pressure, sweting and nausea. is rarely fatal except occasionally in small children and those with specific allergies.    
Tips for Prevention - Building should be in good condition, well sealed and screened. Outdoor lighting should be away from the building or yellow/sodium vapor lamps. Keep premises free of debris that would attract spiders.    
Preparation - Follow tips for prevention. Be prepared to leave the structure being treated for several hours.