Thanks to everyone who shared their advice and comments and voted in the poll about our newest members of the family–our two cats.
The bolder one of the two has been spotted at night and during quiet times of the day (when the children are not around) exploring the house, eating food and hiding under the bed. The shyer cat has yet to be seen, but there was a tell-tale sign of its existence: its fur was stuck to a vertical scratching post we bought. They are alive, and they are watching us.
It was three full days after they came to us that the bolder cat was first spotted. Now it has been nine days. We are all patiently waiting for our new friends to emerge. The kids are especially being patient and are very interested in the rare spotting of the bold cat.
We will be in this house for almost three more year, so they have plenty of time to adjust. I just hope that when it is time to move to our next–and hopefully final–home, that the cats will have fully integrated into our family.