About a month ago we threw a wriggly 40-pound wrench in our placid home life. Hank’s a nine-month-old pit bull mix who loves to curl his entire body into your lap, gets his lip caught in his underbite, and does downward and upward-facing dog stretches that would put a yoga teacher to shame. The five of us—me, Ryan, Hank, and the kitties—are still getting used to each other, but already our household feels more complete.