So Charles, is there a problem if you seal the holes while the rats are INSIDE the house? Any thoughts on this?

Thanks Charles! I've seen those dirt trails along duct work and always wondered in the back of my mind what it was from.  Rat "body grease" doesn't sound appealing, but that makes complete sense.

Al, thanks for visiting my blog, Rats are pretty tenacious and would most likely "eat" their way out.  They can usually make even the tinyest hole bigger.  Better to let the PCO "feed" and/or trap them:)

Jen, once you know what they look like, you find them in places you wish that you didn't:)

I had mice who decided to chew up a rope hammock I had stored in a shed.  They used it to make a nest.  The only problem was the built the nest in the engine of my riding lawn mower.  I'll leave the rest of the story to your imagination.  

Charlie,

The problem I see with this blog you wrote is typical of your negative thinking. That is, it is written under the assumption that all rats are bad. Where is that coming from? Huh? How would this be changed, the tone of it, for example, if you were to assume that some rats are standup guys and gals.

Had some racoons in the attic yesterday afternoon.  Could hear at least two of them rummaging aorund up there.  Didn't stick my head up.  I ain't fussing with them.

One of the poor fellas had fallen into the house as the ceiling woudln't support them.

Steve,  How long does a bag of dog food last for those rats of yours?

Erby, I think raccoons are scarier than rats.  One time I went in the crawl space and when I got far enough from the entryway the raccoon skedaddled out.