The common house spider (Achaearanea tepidariorum) is well-known, thanks to its irregularly shaped webs that are found in the corners of rooms the world over. The spider itself is mostly inconspicuous. The female measures around 5 to 8 mm in length. The males are considerably smaller, around 4 mm.
A common house spider can begin its life any time of the year. The young spider will emerge after around 10 days from one of several pear-shaped, light brown egg sacs hanging in the mother’s web.
The immature form of the spider, known as a nymph, is completed between 30 and 80 days in the male, with an accompanying four to six molts of its outer covering. The female takes between 40 and 100 days, with an accompanying five to seven molts.
The common house spider feeds on a variety of prey that become entangled in its web. The spider seems to prefer man-made structures and may find its web frequently destroyed by householders seeking to rid their home of “cobwebs.” However, the spider poses no threat to humans. Its harmlessness may actually increase human tolerance to its presence.
Scientists from the Tokyo Metropolitan University found that in laboratory conditions, the average life of the male spider was 33.9 days and 116.5 days for the female. This is an average of 75.2 days across sexes. Similarly, scientists from China’s Forestry Bureau of Rizhao City, Shandong, observed the spider in its natural habitat and found that the average lifespan of an adult was 76 days.
The common house spider was first identified in Germany but is actually a native of South America. There are large numbers of the spider in Mexico, Central America and the United States. Scientists from the University of Florida suggest that the species now has a worldwide distribution, having been transported on plants via humans.