Why don't the infected attack each other?
Whilst never clarified in the film itself, it has been explained in the graphic novel, 28 Days Later: The Aftermath, that the infected target their victims through smell. Uninfected individuals smell of perfume, deodorants, soap, etc., while those that are infected would reek of perspiration and dirt. One could conclude that the virus would be counter-productive if an infected individual attacked another infected individual, ergo it has evolved to exclude that possibility. On a more practical level, one could argue that this facet of the Infected is based simply upon the tradition of the earlier zombie films that influenced 28 Days Later, insofar as in such films, zombies are never seen to attack other zombies.
What are the deleted scenes on the DVD?
There are 6 deleted scenes on both the single disc and the 2-Disc Limited Edition DVDs:1. 'London Walk': A minute of additional footage of Jim walking around the abandoned London streets.2. 'Abandoned Train': As Jim, Selena and Mark (Noah Huntley) are walking along the Docklands Railway, they find a 'hospital train', which they proceed to investigate. Inside, Jim finds a mobile phone but there is no signal.3. 'Motorway Carnage': As Jim, Selena, Hannah and Frank are trying to get out of London, just prior to their entry into the tunnel, there is a scene of a flyover with smashed vehicles everywhere, some hanging over the edge and the abandoned city in the background. This scene appears untreated on the DVD as the filmmakers never added the CGI effects to remove the moving traffic.4. 'Taxi/Sweden': On the drive up to Manchester, Jim, Selena and Hannah all take turns driving the cab and acting out the character of a talkative taxi driver. The scene was cut as it was felt the characters had bonded enough and the shot didn't really work. Alex Garland also hated the scene and was embarrassed he had written it.5. 'The Infected in the House': There is an alternate take of Jones' (Leo Bill) death, with the infected overrunning the mansion and killing him. This scene also has Major West shooting Clifton (Luke Mably) and expressing great remorse for doing so. We also see Mitchell (Ricci Harnett) and Selena, looking down into a basement swarming with Infected. The final shot is West bolting a door to prevent the infected getting to him and an infected woman trying to bite her way through the glass to reach him.6. 'Floorboards': During the chase through the house, there is a scene of Jim hiding under the floorboards to avoid Mailer and Clifton.
Twenty-eight (28) days after escaping with Selena and Hannah from the military encampment, Jim awakens in a bed in a countryside cottage, his wound bandaged from the bullet that Selena removed after he was shot in the abdomen by Major Henry West (Christopher Eccleston). A lone fighter jet flies through a valley over a country roadside littered with the bodies of Infecteds dying of starvation. As Selena works on an old treadle-type sewing machine, Hannah suddenly burst in the door and yells, 'It's coming!' In the final scene, the three of them grab a a large cloth banner, run outside, and spread it next to four other banners, spelling out the word 'HELLO'. In the last scene, the jet flies over them, and the three survivors jump and wave their arms to be noticed. As the jet banks back toward them, Selena turns to Hannah and Jim and says, 'Do you think they saw us this time?'