A couple of years ago we were cleaning out a mature bin of compost to make another raised bed garden. We had gotten pretty much to the bottom and there was a mouse nest, with babies in it. Mom had scattered.
Since we caved in the roof with our digging we carefully gathered the babies, (all unharmed) uncovered the nest, put them in and placed a cedar shingle over the top in place of the roof hoping that mom would return and move the babies elsewhere. We quit digging for the day and stayed out of the area.
The next afternoon the babies were moved, we went on digging and thought nothing of it having rather large firewood stacks in the area, we thought that was where they had gone. A few weeks later we note mouse skittles in our greenhouse and a bag of grass seed chewed at the corner. They moved into our greenhouse!
No good deed goes unpunished.
We waited another 2-3 weeks until the babies were old enough to be on their own and cleared out the greenhouse completely, covering their entry points with steel flashing. I would till do the same thing, save the critters and fortunately we don't have lyme disease (or ticks) nor do we have hantavirus to be concerned abut but in Kansas we are getting outdoor (barn) cats to take care of those critters near the house.
I actually like rodents but I don't want them in my house or outbuildings. I think your friend was inhumane and what does she have against those neighbors anyway?

I've caught them like that and let them go outside. Hubby says "why'd you do that for? They will just come back inside" The other day we saw one eating the seeds dropped from our bird feeder. I asked hubby what he would do if he saw it out there again. (I've asked him not to hurt it) and he said he wasn't going to bother it. 

