DID YOU KNOW?

■■ The word “spider” comes from the Old English word “spithra” and is related to the German “spinne”, both of which mean “spinner”. The word “spinster” is also related and means “one who spins thread”.

■■ Cobwebs are simply abandoned spider webs; the word “cob” is an obsolete word meaning “spider”.

■■ An estimated one million spiders live in one acre of land. It is estimated that a human is never more than 10 feet away from a spider — ever.

■■ A spider’s muscles pull its legs inward, but cannot extend its legs out again. Instead, it must pump a watery liquid into its legs to push them out. A dead spider’s legs are curled up because there is no fluid to extend the legs again.

■■ Spiders have blue blood. In humans, oxygen is bound to haemoglobin, a molecule that contains iron and gives blood its red colour. In spiders, oxygen is bound to hemocyanin, a molecule that contains copper rather than iron.

■■ House spiders are able to run up walls because their feet are covered in tiny hairs that grip the surface. But they can’t get out of a bathtub because the surface is too slippery for hairy feet.