The majority of house spiders seen inside are actually born and thrive indoors and would likely not survive outside. There are several different house spiders, but in Ohio the most common ones are the yellow sac spider and the brown or black house spider. Both are harmless, albeit startling when one scampers across the living room floor.
Yellow Sac Spider
This is one of the most common house spiders and is often difficult to spot. It’s light yellow or white coloring helps it to blend into the corner of a wall. Because these spiders are not easily spotted, they can be disconcerting upon discovery, but they are mostly harmless.
Brown or Black House spider
Brown and black house spiders can be startling at times because they are dark in color and can be about the size of a quarter. While they primarily hide in corners and crevices they do venture out sometimes to seek food or a mate. Brown and black house spiders are mostly harmless.