ok,I really don't want anyone to take offence at this because it's just my opinion and I'm playing advocate here.... but, those of you who are objecting to shooting rats, are you vegan / vegetarian? It's a genuine question and just something to think about?
The reason I ask is if you eat meat or drink milk then the animals are killed.... if you drink milk then bear in mind that the biggest bi product of the dairy industry is beef, in the form of the male calves that are born in order for their mothers to produce milk.
I'm a fully paid up dairy, meat eater BUT I understand that animals are killed so they go on my plate. If you are going to complain about rodents being shot then maybe it's worth looking at other opinions you have as well. you've already said you shouldn't have one rule for one animal and another for a different animal
Personally I have a real phobia of Rats and mice and the much beloved deals with the mice with a humane trap..... as far as I know we've never had rats, but I don't think he's tell me even if we had! We leave nuts in a seperate spot for the squirrel and he seems to leave the feeders alone! We don't mind him visiting, the kids will sit for hours quietly watching out for him!