Which house bugs are venomous?

These have venom that can harm people. 7 house and yard pests on Bug FAQ, most commonly seen first. Each line is quoted from that bug's page and its sources.

Western Black WidowLatrodectus hesperusVenomous
The female western black widow can deliver a medically significant bite with neurotoxic venom that causes pain, nausea, vomiting, goosebumps and sweating.
Source: Wikipedia, urbanipm.montana.edu
Red Harvester AntPogonomyrmex barbatusVenomous
Red harvester ants can sting people and pets, and their venom can cause painful reactions and occasionally dangerous allergic responses.
Source: Wikipedia, extension.unr.edu
Southern Black WidowLatrodectus mactansVenomous
Southern black widow females can bite people, causing pain but rarely fatal effects.
Source: Wikipedia, UF/IFAS, Penn State Extension
Southern Flannel MothMegalopyge opercularisVenomous
It can sting people with venomous spines causing painful reactions.
Source: Wikipedia, extension.msstate.edu
Brown RecluseLoxosceles reclusaVenomous
It can cause serious skin necrosis and occasional systemic illness in people.
Source: Wikipedia, Penn State Extension
Northern Black WidowLatrodectus variolusVenomous
Its bite can cause painful symptoms that may require medical attention, though death is rare.
Source: Wikipedia, UC IPM
Arizona Bark ScorpionCentruroides sculpturatusVenomous
Its sting can cause severe pain, numbness, vomiting and can be life-threatening.
Source: Wikipedia