I used to live in a beautiful Texas subdivision, right on the golf course in fact and we had a roof rat problem as well as a squirrel that'd sneak into the attic. I found where the squirrel was getting in and a small Conibear trap over the opening made short work of him. Then I screened off his entry. The rats were harder because they could get in through smaller openings so I put 3 snap traps out baited with peanut butter and within a few days no more rats. Then I searched out the entry ways and sealed them up.
The last thing you need is one of those filthy disease spreading critters dying in your attic, and yes they do make a stink when that happens.
Steve