Spiders are common in homes throughout the world. Connecticut, like other U.S. states, has several species that may wander into the home, along with a few who prefer the indoors. Spiders often wander indoors--males especially--during mating seasons, to find shelter during cold Connecticut winters, or they live there regularly because of a dependable food source. All spiders may attempt to bite if provoked in some manner--including being trapped against your skin in sheets or clothing--but are not aggressive to the degree of actively searching out a human to bite.
A European invasive, the house spider is a common housemate in Connecticut and across the country. Responsible for many "cobwebs," at 1/8 to 1/4 inch the American house spider is not particularly large or small. Although this spider is in the same family as the dreaded black widow, it's venom is not considered dangerous, although reports of allergic reaction have occurred. The spider has a large round abdomen and thin legs.
The wolf spider family is very large and often takes an expert to distinguish individual species. Although these spiders prefer the outdoors, they are not uncommon inside the home especially during colder months when they seek the warmth and shelter of a house. These spiders intimidate some, with their formidable appearance and quick speed. Wolf spiders do not build webs, they are active hunters. An interesting characteristic is that their eyes are reflective, allowing them to hunt at night and be seen by the light of a flashlight or other light source.
Sac spiders receive their name from their choice of homes. They do not build webs, but instead small sacs in corners typically high above the ground. Sac spiders are generally pale yellow, yellowish-green or beige in color, and a few species are commonly referred to as "Yellow Sac Spiders." Nocturnal, these spiders often run quickly along walls and ceilings. If they are disturbed, they will quickly release and fall to the floor. Sac spiders are medically significant, their bites can leave necrotic wounds, similar--but often not as dangerous--to the bite of the Brown Recluse or Hobo Spider. (Connecticut is not in the living range of the Brown Recluse or Hobo Spider).