Spiders produce up to seven types of silk.
One of the most commonly produced silks, called dragline, is used as asafety line by most kinds of spiders. Gravid female orb weavers have largeabdomens and are heavy enough that a hard impact could be fatal. The worstcase scenario would be a fall with a preformed length of silk and no additionalsilk spooled by the spider. Tests of the material properties show thatthe dragline produced by the adult orb weaver Araneus diadematus would indeed break during such a fall. To explain this apparent discrepancybetween material property and function, I am measuring silk spooling ratesas well as friction forces associated with spooling.