It is one of at least two common spiders found in houses known as lace-webbed spider. The specific name similis is based on its similarity to the species Amaurobius fenestralis. Both are often found near windows, hence the specific name of A. fenestralis. The two species are difficult to distinguish: A. similis tends to be larger and darker in colouration when an adult, and prefers the indoors. Both species have V-shaped markings on their abdomens, with A. similis usually having four, and A. fenestralis two or three. Examination of the genitalia may be needed for precise identification.{{citation needed|date=October 2016}}

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