After a devastating nuclear war humanity is split into two groups- those above ground and those below. A group of survivors come upon a deserted building and decide to make it their home. Little do they know that the building is already inhabited, and it may be no surprise to you that the inhabitants are rats.
There's not much to say about this movie, other than that it is awesome. I can't believe that this is from the same guy that gave us the hilarious (but terrible) Hell of the Living Dead. Rats is like Night of the Living Dead, with the the survivors replaced with nuclear holocaust survivors and zombies replaced with rats (Hell of the Living Dead, on the other hand, is Dawn of the Dead with the survivors replaced with insane Italian macho guys and the zombies replaced with zombies plus cannibals). I don't even think there was any stock footage awkwardly inserted into Rats!
Although on the surface it's your typical "bunch of people stuck in an increasingly dangerous small area" kind of survival picture, it's a pretty interesting entry in the genre due in no small part to the usual Italian exploitation movie lunacy (characters that only act sort of like people, unbelievable deaths, hilarious dubbed macho talk)... but more importantly, due to its unique combination of survival and a post-apocalyptic movie themes, topped off with a ridiculous twist at the end complete with ham-fisted social commentary.
Since it's a cheap exploitation movie, there are some things that don't work so well. The rats don't seem particularly blood thirsty, they kind of just wander around and even when someone off camera throws them at the actors, they kind of just fall to the ground and try to escape. At one point the rats start orchestrating pranks against the humans in order to terrorize them, such as moving dead bodies around or climbing into a dead guy and moving him around like some kind of giant robot for rats. And there is one woman in the group who is absolutely hysterical and at one point she just sees a spider and just loses it and you have to wonder how she even managed to survive a nuclear apocalypse.
All in all though it's one of the better Italian post-apocalyptic survival horror movies!