The scientific name of the common house spider is parasteastoda tepidariorum. This type of spider has worldwide distribution and the good news is that common spiders are quite harmless. Even when they bite, which they do when they feel threatened, their bites are typically a minor irritation.
Size of a common house spider
A female house spider can measure five to eight millimeters in length while the male is smaller in size measuring four millimeters. The females tend to be bigger because of reproduction purposes.
The common house spiders are usually gray or brown in color. Their legs have black rings and their abdomen is usually dotted with white markings. You will find them having built webs in the dark corners of your house especially in rooms that are not commonly frequented like the attic. But you will also catch a web or two in your bedroom or bathroom.
A common house spider has a specific natural habitat: man-made shelters. They live indoors but that can be anywhere from a house to a barn, shed or the house basement.
These spiders love to crawl and skitter along the walls and floor. They build their webs thicker on one side compared to another and sit on the thicker side to mount an attack on their prey. The web is made from silky strands and you may notice several cob webs in the same corner of the house. This typically occurs with house spiders that have found a source of a lot of food. They can share the space and co-exist together. But just like venomous spiders they will attack each other when competing for limited food supply.
During the breeding season the male and female live on the same web to facilitate mating after which the male dies off leaving the female to lay her eggs. The female will hold the male’s sperm for a while until she is ready to fertilize her eggs.
The female lays eggs several times a year. You can see a sac of the eggs clearly in the summer time and they appear as small brown dots hanging off the web. Each egg is fertilized individually and placed into a sac which can hold up to 400 eggs.
Common house spiders reproduce at a high rate so you may notice their populations growing alarmingly in your house within a few weeks to months.
House spiders go through three phases of growth to reach maturity. They are laid as eggs then they hatch into spiderlings which then mature into adult spiders. They will molt five to ten times before the spider reaches full maturity and at maturity their exoskeleton will be harder for better protection.
The male needs to approach the female carefully or he will be attacked.
Common house spiders are not threatened with extinction. Their populations are healthy and well distributed all over the world. These spiders help keep out insects like flies but when they become too many they become a menace.