When school ended, the 10-year-old classroom degu (South American rat) came home with us. The teacher told us that Cedar, named for her reddish fur, might not survive the summer, given her advanced age, in which case we should freeze her (near the cool-pops?) until fall, when she would get a proper school funeral. I did not fall immediately in love with this creature, despite her being cute, caged, fairly clean, and friendly. Instead, I clicked into the Oxford English Dictionary, to learn that a degu is “a rat-like animal, rather smaller than the Water Vole, the head and body measuring from seven and a half to eight inches in length.” A definition often makes me fonder. Now I like Cedar, sort of, and having her around has made me curious about the new book Central Park in the Dark: More mysteries of urban wildlife. Who knows, maybe Cedar has dozens of cousins in New York City.