Guano Apes is a female fronted alternative rock quartet from Gottingen, Germany. The Guano Apes were formed in 1994 in Gottingen, Germany, by guitarist Henning Rumenapp, bassist Stefan Ude and drummer Dennis Poschwatta. Lead singer Sandra Nasi? joined the band later in the same year. The band's career took off in 1996 after they won a contest for local unsigned bands with their song 'Open Your Eyes'. The song was also their first and most successful single, followed by the release of their 1997 debut album Proud Like a God. "Open Your Eyes" also appears in the Warren Miller movie, Fifty (1999). The single 'Don't Turn Your Back On Me' was contributed to the Meschugge film soundtrack in (1999).

In 2000 Guano Apes released their second full-length album, Don't Give Me Names. The singles "Big in Japan" (an Alphaville cover) and "No Speech" received a lot of airplay and the album was certified gold in Germany. Walking on a Thin Line was released in 2003 and spawned the hit single "Quietly". The band broke up after the release of their best of album Planet of the Apes and a final tour in February 2005. After the break-up, a compilation album Lost (T)apes was released. It contains unreleased demos recorded in 1994 and 1995.

Dennis Poschwatta focused on his new band, Tamoto, in which he played the guitar (and drums on the album) and shared the vocal microphone with Markus Gumball a.k.a. G-Ball. Stefan Ude also participated in the recording of Tamoto's debut album. Henning Rumenapp focused mainly on working 'behind the scenes' and Sandra Nasi? started working on a solo album called The Signal (released October 2007).

In 2006, Rumenapp, Ude and Poschwatta reunited and formed a new band named IO, together with American singer Charles Simmons. The band has been on the road several times since then and has also been writing and recording material for their debut album, which is yet to be released. Due to the busy schedule of IO, Dennis Poschwatta's other 'new' band Tamoto has been put on ice until further notice.