The photo of Steatoda nobilis in the previous entry shows a female with the classic pattern of this species. However, here is the other, smaller False Widow, Steatoda grossa, which has a similar pattern, but with a row of triangles in the middle rather than a big pale patch.
So here are the best ways of recognising False Widows:
1. The spider’s abdomen is generally very shiny, like a berry. The spider is hairless.
2. False Widows don’t just hatch out of an egg fully grown. They can be very large, up to 2.5 cm (just short of an inch) when pregnant, and any size under that.
3. The web is a hammock-type web, but unlike the similar Hammock-web Spider, the web of the False Widow is EXTREMELY strong.
4. The spider always hangs upside down from its web.
5. Apart from the male Steatoda grossa, which is a fast runner often wandering into houses in spring (he doesn’t bite for some reason and will happily let you handle him) the female S. grossa and both male and female Steatoda nobilis are extremely slow and clumsy on the ground and actually slip when they walk on smooth surfaces.
6. The False Widow pulls its legs in tight, forming a ball, if knocked from its web or handled. Biting is the very last resort.
7. Both species have two very shiny eyes located at the top front of their heads which virtually glow in torchlight and are among the first things you will notice.
False Widows rest under crevices, usually only coming out at night when birds won’t see them. Birds have no difficulty eating any spider that will fit in their mouths. Anything resting against a wall, or in a sheltered area, or on the outside of a house especially under the eaves will be an attraction to a False Widow. They will enter sheds too, but outside if their preference.
8. False Widows are not afraid to be outside on even the coldest, frostiest nights. It was assumed, because they originate from the Canary Islands that they would fear the cold, but I have seen them outside in their webs when the temperatures were below freezing.