Any of the insulation that has been pissed on by the rats needs to go. . . .. . I have been told by a couple of different exterminators that more rats are attracted by the smell. . . ..

Anothere thing they are attracted to is dog sh!t, apparently they like to recycle waste. . ...

I like the simplicity of the good ole rat trap. . ... nothing like hearing one go off and finding it full of twitching rodent. ... . . . just be sure to set them where they are most likely to catch only rats (not birds, Douglas squirells, etc .. . ). . . .

I hate rats, they pulled the screens off some of the bird blocks on my shop and tried to take up residence. .. . . . .trapped six of them (and one Stellar Jay, sorry buddy) and replaced the screen with hardware cloth. All better now .. .