Wes Craven and producer Peter Locke originally wanted to film the new version in the exact same desert location as the 1977 film but when they went out to scout the locations they found a number of condominium developments had been built.
The mutants were created by CGI, physical effects or both. Most of the mutants with full deformations were created by prosthetic makeup. But the deformed children who were playing were digitally distorted using tracking dots on their faces. Ruby was a mixture of the two, using the tracking dots for distortion and prosthetic teeth.
This movie and the original were inspired by the legend of Alexander "Sawney" Bean, the psychopathic head of a Scottish clan that reportedly killed 1,000 people to feed their inbred brood. Bean and company would set booby traps for travelers and then attack. Eventually, the disappearances drew the attention of King James VI, who put an end to Bean's reign and massacred his entire family. Although some say the whole thing never happened and was a smear campaign by the British, many still believe in the "Sawney" tale.
The making of featurette on the DVD indicates that at some point during production, the character of Papa Jupiter was going to have a parasitic twin jutting out of his chest. The effect was scrapped for the final film, leaving him the only one of the "mutants" without any apparent mutation.
Alexandre Aja and art director Grégory Levasseur originally planned to film in Morocco because of its similarity to the New Mexico desert. Initially the producers objected to this, for fear of terrorist attacks, but after Aja and Levasseur failed to find suitable locations in the US, they relented.
Nivek Ogre (Kevin 'ohGr' Ogilvie) of industrial/goth group Skinny Puppy auditioned for the role of Lizard but didn't get the role as he claims to have been way over the top and scared them. "I really like the remake of The Hills Have Eyes. I auditioned for that!" [Which part?] "Lizard. I was in all their faces, I went way over the top and they were scared of me, but they sent back really good feedback to the agency I was with at the time."
The trivia items below may give away important plot points.
With the Aaron Stanford character, the filmmakers were looking for someone similar to Dustin Hoffman did in Straw Dogs (1971), where Hoffman was an ineffectual nerd who rises to heroism in the end and commits ghastly acts of violence. Stanford in the films also markedly physically resembles this films director, Alexandre Aja.