The giant cockroaches that cover the surveillance camera lens at 71:47 on the DVD are not Computer Generated. Director Robert Shaye mentions in the commentary that the production employed three "cockroach wranglers" to handle the insects.
The Last Mimzy is based on Mimsy Were the Borogroves by Lewis Padgett, published in 1943.
During the 2012 Savannah Film Festival, Robert Shaye held a Q&A session after a screening of the film. During the Q&A, he stated that he was not a fan of the film's title. He and other producers came up with a new title, "The Gifted", but it was too late in the production process to change it.
La colline a des yeux 2 (2007) was accidentally shown in a theater session of The Last Mimzy in Holtsville, Long Island back in April 2007. The audience members were mostly made up of young children and their parents having to watch the graphic birth scene of the mutant baby at the start of the film. The theater employees were unaware of their mistake until they saw people running out of the theater room crying and screaming. The theater apologized and offered movie vouchers and free counseling services to all of the audience members of the misplaced film.
When Noah first controls a spider at the beach house (at around 19 mins), director Robert Shaye mentions in the commentary that Visual Effects Supervisor Eric Durst "got hold of the special effects house in Australia that did all of the visual effects for Le petit monde de Charlotte (2006) - they happened to have the computer program for making spiders crawling on webs."