Termidor They use it for termites but it works for ants and spiders. It is spendy, but it works awesome. Put in tank sprayer and a gal of water. I spray a 3 feet area all around the house. Zero ants or spiders. You need to reapply after it rains though.

http://www.amazon.com/Termidor-SC-20.../dp/B002ZUCUGU