Infest the Rats' Nest is the fifteenth studio album by Australian psychedelic rock band King Gizzard & the Lizard Wizard. It was released on 16 August 2019 by the band's record label, Flightless, and ATO Records. The album sees the band using a heavy metal and thrash metal style, which they had only briefly touched upon on previous albums. Its lyrics address environmental themes such as climate change and ecological disaster through a cli-fi narrative involving space colonisation. The album received generally positive reviews, with critics highlighting the performances and themes, and was nominated for the 2019 ARIA Award for Best Hard Rock or Heavy Metal Album. The album charted in several countries, including peaking at number 2 on the ARIA Charts and number 3 on US Independent Albums. Background and release Australian rock band King Gizzard & the Lizard Wizard released five albums in 2017, concluding with Gumboot Soup in December. Following a brief hiatus, on 21 January 2019 the band teased their fourteenth studio album, which would later be announced as Fishing for Fishies. Prior to its full release on 26 April 2019, the band surprise-released single "Planet B" on 8 April alongside a music video. The song's exclusion from the album's track listing and distinct sound led to speculation that the band might release a second album in 2019. During a question-and-answer on 30 April with fans on Reddit, the band confirmed the next album was at an early stage of production and would include "Planet B", but they had not decided if it would be released in 2019. The album was speculated to be titled Auto-Cremate, the band's username on their Reddit Q&A. On 29 May, the band released the album's second single "Self-Immolate" with another accompanying music video a week after a teaser on social media. On 18 June, the band posted another teaser on social media which confirmed the album's title. The album was officially announced three days later with a release date of 16 August. On 25 June, the band released a third single, "Organ Farmer", along with a music video that included fans as extras. The album was released on August 17 on Flightless and ATO Records. Composition Music Infest the Rats' Nest was composed and recorded primarily with only three of the band's usual seven-man lineup. Stu Mackenzie and Joey Walker recorded all guitar and bass parts, with Michael Cavanagh playing