Which house bugs are venomous?
These have venom that can harm people. 8 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 hesperusVenomousThe 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 barbatusVenomousRed 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 mactansVenomousSouthern black widow females can bite people, causing pain but rarely fatal effects.
Source: Wikipedia, UF/IFAS, Penn State Extension
Southern Flannel MothMegalopyge opercularisVenomousThe Southern Flannel Moth’s caterpillar can deliver a medically serious sting.
Source: Wikipedia, extension.msstate.edu
Brown RecluseLoxosceles reclusaVenomousMost bites are minor, but a small number cause the skin around the bite to die. Less than 1 percent cause illness through the body, such as anemia or kidney injury.
Source: Wikipedia, Penn State Extension
Northern Black WidowLatrodectus variolusVenomousIts bite can cause painful symptoms that may require medical attention, though death is rare.
Arizona Bark ScorpionCentruroides sculpturatusVenomousIts sting can cause severe pain, numbness, vomiting and can be life-threatening.
Source: Wikipedia
Desert RecluseLoxosceles desertaVenomousThe desert recluse can bite and its venom may cause serious skin lesions.
Source: Wikipedia