Rats, raised in clean conditions and fed properly, would probably make a good food source. People eat rabbits and squirrels, there's really not much difference.
True, but what you consider clean conditions is relative. City streets are dirty, but so is the bottom of the ocean! where sharks vacate and whales rot to bits and all kinds of sediment and detritus gathers: there's your market price lobster's "clean conditions and properly fed". So would you knowingly eat a rat off the city streets? Well, I probably would too in fact, even if the thought truly disgusts me :}
It is all pretty disgusting, be it bottom-feeders or beef in the lot. Our protein sources are generally grown and nourished in close vicinity to massive amounts of faeces. At least lobster is free range.
I think the idea of producing cricket meal as a protein supplement/food additive is pretty novel, but it will be a long time before I cook with it directly.