After jamming together in 2000, Merenda, Ungar and Rodríguez-Seeger formed the Mammals in 2001. They first performed as a quartet with Alicia Jo Rabins on the fiddle. In 2002 and 2003 they became a trio, adding bassist Pierce Woodward, and drummer Ken Maiuri on some of their performances. Chris Merenda, Mike's brother, joined the band in late 2004 replacing Maiuri on the drums. Woodward left the band in 2005 and was replaced with Dan Rose, who was replaced with Jacob Silver as the Mammals current bass player.
The Mammals often include guests in their live shows, such as Rosie Newton; Peter Siegel; Tao's sister, Penny Blossom Seeger; Jay Ungar and Molly Mason, and Pete Seeger. Aoife O'Donovan performs backing vocals on their CDs.
Mike Merenda is the band's main singer/songwriter and vocalist, and multi-instrumentalist, playing guitar, banjo, ukulele and percussion. His songs often address political and environmental concerns; topics such as government upheaval, war, the environment, and presidential catastrophe. Merenda's song The Bush Boys has caused The Mammals to be censored at some festival venues. His songs often tell stories drawing on personal events, such as the songs Haircut Money and 69 Pleasant Street.
Ruth Ungar performs on vocals, fiddle, and ukulele. She is a songwriter for the Mammals, and her songs center on themes of fair trade and the environment. Her song "Four Blue Walls", inspired by the play Danny and the Deep Blue Sea was featured on an album by Canadian band The Duhks.
Chris Merenda is the Mammals drummer and the younger brother of Mike. In addition to percussion he plays the guitar, banjo, piano and sings vocals. He occasionally plays the ukulele. Chris has released two solo records titled The Regimen (2003) and Hello Freedom (2005). Jacob Silver plays electric and upright bass.
Music is music. People think that The Mammals have pushed and broadened the boundaries of folk music. I think we've barely even started. There are no boundaries. There are conventions.
Mike Merenda said
We've been called a band that takes old music and makes it sound new. On this album [Departure] we take new music and make it sound old. We play these instruments because they're the instruments we know how to play, but what's exciting is to take them out of the realm of expectation.
They tour the United States on their "Western Migration Tour", visiting cities on the West coast and in the Midwest and southern United States and during the summer months they play at many folk festivals, including Newport Folk Festival, Telluride, Philadelphia Folk Festival, and Magnolia Fest in Florida. When possible, The Mammals pair up with the Duhks to form Platypus.
Ungar and Mike Merenda married in October 2006 and perform together and with Jay Ungar and Molly Mason in the Jay Ungar and Molly Mason Family Band.
Ungar performs in Sometymes Why and the Wayfaring Strangers.
Ungar, Mike and Chris Merenda have solo CDs. Chris Merenda also fronts an indie rock band called Chewy.
They have released four albums, and two EPs. The most recent two albums have been released on Signature Sounds: