They are in my two-story townhome. I hear them when I am downstairs. Also one of the cats has been observed in stalking mode in the kitchen for hours at night. I plan to address this via a light outlet or two in the downstairs ceiling. Has anyone heard of the approach below? Any other suggestions?

Back around 1996, a "Michael" posted the following:

You can get [good rodent control toxin] from the pest control professionals in your area. It comes in a small-ish paper bag with poisoned food inside. The poison makes the rodent thirsty. This usually makes them leave your house (in search of water) before they die.

You just put the whole bag in a place where your rodent friends frequent. The'll eat through the bag. This is how you be able to tell if they've taken the bait.