Rats in the attic, killed?

Hi

How did they get there? We have nothing to take them there. They've already been to our neighbors' house; they live in a semi-detached house. My father (I can't call him anything else because this story makes me somewhat loathe him) got rat poison from our neighbors and spread it in the garage and attic. He even forced me to help spread it! (Of course, I didn't; my mother had to go along.)

We kept telling him to please stop, that animals have feelings too, and that they should use a live trap. He complained about how they transmit diseases and are terrible. Sure, maybe they transmit some, but the problem we have now is much worse.

My mom, sister, and I are vegetarians, so it's very painful when animals have to die because of someone like that. He's not a good person at all anyway.

The rats died miserably in the attic, and it smells unbelievably of decay. There's a draft all the way into the bathroom, so the attic is above the bathroom.

Is it bad to breathe in the smell, and how can we remove the poor creatures without introducing any bacteria? I assume, as the neighbor said, that they bled to death. 😢