Robert E
Roof rats are great acrobats, climbers and always nest over our heads. Roof rats can chew wood, and can squeeze easily through spaces smaller then a US Nickel and can exploit small openings to access any home and often prefer attics over tree nest here in Florida.
In many ways roof rats can do whatever a gray squirrel can do and sometimes I even felt they were better. I found roof rats less neophobic compared to the Gray Squirrel and Norway Rat. I found they could often be gang set with snap traps and hit with the glue board strips (like I demonstrated in my snake trapping class last fall) in the rafters and air ducts where I observe feces and activity.
Its been awhile since I have done any roof rat work here ( we have cotton rats, woodland voles and common house mice) but down in Sarasota there was always more roof rat work then there was time in the day.
Residential work. Do the exclusion and begin getting rid of whats in the structure first. I prefer snap traps over live cages. I have used most anything edible to catch or capture them:
Peanut Butter, Rancid Bacon, Kiwi, Oranges. Bread. Sometimes I catch them by just baiting a treadle with whatever they are eating and tying it off with thread.