In a February 17, 2010 interview with the Artisan News Service, lead singer Stephen Pearcy said of Infestation: "We wanted this to be like something that we would have written right after [1984's] Out of the Cellar. We definitely went back to basics with the mind set of a band with a lot of excitement and some great songs to get out."
In a March 18, 2010 interview with Metalholic Magazine, guitarist Warren DeMartini said of Infestation: "It really exceeded our expectations. Conceptually we kind of wanted to revisit the period of Out of the Cellar and Invasion of Your Privacy. We were sort of loosely trying to shoot for something that could fit between those two records. We were looking for more uptempo ideas and the double leads that Robbin Crosby and I started doing back in 1983."
In the US, the album debuted at No. 30, selling around 14,000 copies, making it Ratt's highest charting album since 1990. The album has since gone on to sell over 50,000 copies in the US. In Japan, the album charted at No. 5. The album also reached No. 49 in Finland, No. 55 in Canada, No. 78 in Switzerland, and No. 139 in France.