The Unfortunate Mazda 6 Design That Attracted Spiders

At the heart of this problem was the yellow sac spider, a particularly common variety of spiders in the Americas. Yellow sac spiders are nocturnal and prefer tube-shaped sites for their nests, where they weave silk shelters to wait out the day (via AnimalDiversity.org). These particular critters also use hydrocarbons as important scent markers (via Behavioral Ecology). Gasoline is very much a hydrocarbon — and, unfortunately for Mazda, its Mazda 6 vent lines were releasing just enough gas aroma to lure in the spiders, as reported by Reuters more than a decade ago. 

The first recall over this problem involved an attempt to mitigate the issue by installing a spring in the vent lines. That didn’t work as well as planned and the spiders still managed to block them with webs. Apparently giving up on the effort to keep the spiders out, Mazda instead announced that its second recall would involve a software change so that if spiders did cause a blockage, it wouldn’t result in the build-up of pressure that could crack the fuel tank.

Thankfully, only a few cases of actual damage were reported before Mazda issued the first recall. In 2014 when the second recall arrived, Reuters reported that the spring-based solution had been successful “for the most part,” but that nine cars still experienced damaged fuel tanks after the solution was implemented. That ultimately spurred the second software-based fix. Fortunately, the automaker had said at the time that it wasn’t aware of any fires that may have resulted from the spider problem.