Spider species that are frequently encountered indoors are commonly referred to as “house spiders.” However, many spider species that are commonly found within homes prefer to live outdoors. Most spiders found indoors are actually outdoor species that accidentally wander into homes. For example, many wolf spider species are found within homes often due to their habit of constantly and rapidly pursuing prey over large areas of land. Since wolf spiders are common on residential lawns where large amounts of their insect prey can be found, their busy feet often bring them into homes inadvertently. Domestic house spiders, on the other hand, are well adapted to indoor environments, and they may die if placed outdoors.
Encountering a spider within a home can be a frightening experience for many people, but spiders reduce the number of insect pests within a home, and the vast majority of spider species are considered harmless to humans. If a potentially dangerous spider, like the northern black widow, is spotted within a home, then a pest controller should be contacted for the spider’s removal as well as an inspection of the rest of the house. Spiders do not usually become abundant indoors, but it is not uncommon for residents to find one or more spider egg-sacs within their home. Just one spider egg-sac can contain anywhere from 50 to more than 200 eggs, depending on the species. When a spider egg-sac is spotted within a home, a professional pest inspection should be carried out so that all eggs can be removed from a home before they hatch.
Most spider species that are well known for dwelling within homes are capable of laying hundreds of eggs at a time within a sac-like structure. Individual female spiders sometimes lay up to 9 or 10 egg sacs within a home. One of the most common groups of spiders found within homes are cobweb spiders that belong to the Therididae family. While indoors, these spiders lay around 10 egg-sacs that are kept in the female’s web or carried on her back, and each sac contains around 200 eggs. Cellar spiders are sometimes referred to as “daddy long-legs,” and they, along with jumping spiders, lay around 20 to 30 eggs per cocoon. One single female American house spider will deposit around 250 eggs into a brown-colored silk sac on her web, and these eggs hatch spiderlings within one week and survive for one year. When it comes to web-spinning spider species, egg-sacs are usually found on webs, while solitary spider species typically see females carry their eggs below their abdomen or on their back everywhere they go.
Have you ever found a spider egg-sac within your home?