Most are beneficial because they feed on insect pests, such as cockroaches or house crickets, and should be left alone. A few may be of concern, however, because they have a venom which may be poisonous to humans. The males also have the red hourglass on the underside of their abdomen, but are cream and tan in color and much smaller in size. Newly hatched black widows are white with black spots on their abdomens with a cream-colored hourglass. Later, as they mature, they become cream and brown striped.
All stages are venomous.
Even the egg sacs contain poison, and should be carefully removed and crushed. The spiders hide during the day and hang upside down in their webs at night. Be cautious when picking up or moving objects, particularly in sheds or garages. Also, check clothing before putting it on. Although bites are generally not fatal, they should be considered dangerous and medical attention should be sought immediately.