Just want to mention once more that you can't control rats by trapping
or killing them outside. Killing those inside and making the house
rodent-proof is about the best you can do; there are people who
specialize in this. But if you have a bird feeder or any source of food,
you can't really eliminate rats from the outdoor world (which is great
job security for exterminators). I think what Bill meant was removing
brush and veg in the immediate vicinity of the foundation, because rats
would rather stay near cover and not cross open space.

I live with some super affectionate pet rats, so it's always a little
tough to read about control methods that make them suffer. They are
really intelligent and playful critters, just taking advantage of the
habitat we provide. I'm lucky--I have rats inside, and deer mice
outside (okay, inside too sometimes).

Angela Percival
Olympia, WA
Angela at stillwatersci dot com