Several other common spiders are mistaken for the false widow Steatoda nobilis in the UK. The two confused most often are the missing sector orb weaver and the lace web spider.
This very common and widespread species loves to make its web over windows and uses the corners of the frame and the sill for its refuge. Most homes in the UK are likely to have this species in residence.
Lace web spider, Amaurobius species.
These spiders are completely harmless and through the year they will catch a lot of insects and other invertebrates that have greater pest status. They are also one of the few species that happily feed through the winter, if insects are available.
Several species of lace web spiders are common around the outside of our homes and gardens. They make a characteristic lace-like web on fences, sheds, walls and among general clutter around the garden.
Males are prone to wander indoors when mature and looking for a mate. Bites have been reported when a spider has been trapped against the skin, but with little pain or lasting symptoms.