Sac spiders are found throughout Australia, and are often encountered inside houses or in outbuildings. They are known as sac spiders because they construct a small sac from silk, into which they retreat when not active, usually during the day. This sac is typically attached to the substrate in crevices, such as behind pictures or between a window frame and sash, or in the angle between a wall and ceiling. This spider has a reputation of being able to deliver a bite which results in severe pain, redness and swelling, as well as systemic effects such as nausea.