The Skepticism of Rats

(Cross-posted to http://erantravels.blogspot.com )
Here’s an exercise in creativity. How would you start the following sentence?
“…, as rats are very skeptical of new things.”
Yes, it’s a real sentence I came across. Seriously. Stop for a second and think about it. What would be a good opening for it? Here are some of mine:

Don’t try confidence games [...]