Spider Spins Ant-Repellent Silk

bazzalunatic writes "The common golden orb web spider wards off ants from attacking it on its web by spinning an ant repellent (pyrrolidine alkaloid) into its silk. It could be used to develop a new insect repellent for humans. 'This study is among the first to show animals incorporating a chemical defence as a response to the threat of predation,' says Professor Mark Elgar of the University of Melbourne."

Re:Spiderwebs and ants...?

[Dunbal]

A spider will eat one ant. It has trouble coping with thousands or even hundreds of thousands of ants at a time, however. I think the defense mechanism is to avoid the spider getting ambushed by a roving ant army, but any lone ants can be dealt with with the usual efficiency.