Spiders commonly enter homes in two primary ways: entering through open, poorly screened windows and doors and through cracks and gaps around door and window frames.
Some spiders like moisture and are found in basements, crawl spaces and other damp parts of buildings. Others like dry, warm areas such as subfloor air vents, upper corners of rooms and attics. They hide in dark areas.
Tens of thousands of spider species have been identified throughout the world. These spiders have eight legs and two body segments. Spiders have three or four pair of eyes. Many spiders have poor vision, but some species of spiders, such as the jumping spider, have exceptional vision.