大象传媒

David Attenborough tells us that some spiders don't make webs, but still use silk. A female wolf spider trails a dragline of silk in case she needs a safety line. But the male wolf spider has another use for it: he can 'taste' her silk with his palps and find out if she is ready to mate. Once in sight of her, the male has to do an elaborate pattern of signals to the female, waving his palps in a kind of semaphore message. His heartbeat triples while he does this. If she likes the display she'll tap her legs to encourage him. He climbs on her and uses his palps to pump his sperm into her as they mate.