Hi, saw your post about rats, would have gone through the entire posts but kinda tired, its been a heavy day. I'm into pest control and i have a solution for you. Rats just don't appear in you house, they find a way to get in. Now, you need to follow these steps.

1) find and block all access route used by the rats with materials that they cant chew. If you cant, get an expert carpenter to help you.

2)find other possible places that are identical or look like a possible route and block with the same material. Rats will find alternative routes when former is blocked

3) For non chemical rodent bait approach you can buy the common rat glue that is been sold around and place them at strategic rat routes to take care of those trapped in the house that cant get out.

4) if they are very big, I'm sorry to say the glue might not work because of their size. You can get the common rat traps and place food stuffs like fish, crayfish or cooked food to attract them.

5) Another option is to get a professional pest control company to handle you problem.

With these simple methods you can keep you house rat free. When i moved into my new house, i realised my environment was good for rats to breed in large number and become a problem to me. I just made sure that all windows and doors were properly fitted so that rats cant get in and its been 2 years and not a single rat in my home but i see them running around the neighbourhood. You also need to insure all windows and doors are properly shut at all times.

i wish you the very best.