Jumping spiders use their legs to communicate courtship interests to potential mates. The miniscule impacts of spider legs tapping against the ground surface are detected by nearby spiders. This "drumming" cadence signals the spider's reproductive interests. The female detects the low frequency vibrations through her legs. She responds by allowing the male to mount her.
Heâ€™s got the moves, alright. Push play or go to Videosift. More jumping spider courtship dance videos here. -via Cynical-C