Moving back legs

[Justinterested]

So I am in the UK and noticed a small spider (roughly an inch or so) in my kitchen that was holding both its back legs in an almost circular shape and bringing them into its body quite quickly and repeatedly for a few minutes without stopping. I was wondering what behaviour this is? It appeared female from my really limited knowledge as it was quite bulbous and had no visible pedipalps.

 

[Jess S]

Hi there. Sounds to me like it was webbing. Spiders use their back legs to pull silk out of their spinnerets in just the motion you describe either to make webs or to wrap prey items. If you didn't see it holding prey it was probably busy making a web. The bulbous abdomen is often a clue that it is a web spinning species. There are probably exceptions but most web spinners do have quite fat abdomens!

 

[Justinterested]

I was unable to see any Web being released and it was already on a Web it had leading behind the back of a cupboard. It continued to do this even with me standing within a few inches of it. It is definitely a Web spinning species they are extremely common.

 

[Ungoliant]

So I am in the UK and noticed a small spider (roughly an inch or so) in my kitchen that was holding both its back legs in an almost circular shape and bringing them into its body quite quickly and repeatedly for a few minutes without stopping. I was wondering what behaviour this is?

That sounds like the web-making behavior of a cribellate spider.

Cribellate spiders have a modified silk spinning organ that consists of a plate of thousands of spigots (called the cribellum). This produces extremely fine strands of silk, which the spider then frays by combing with the calamistrum (a set of special bristles) on the hind legs.

This is a slow, laborious process, but the resulting silk is extremely sticky despite not having any glue. It often has woolly or tufted appearance.

@basin79

 

[Justinterested]

Thank you very much for your replies, that is exactly the behaviour I witnessed.

 

[Justinterested]

She's at it again right at this moment, although her Web doesn't appear any different. I am beginning to be fascinated by this little guest lol.