Deep within the humid, layered canopies of eastern Madagascar's coastal rainforests, an evolutionary anomaly awakens as twilight recedes into total darkness. Clinging vertically to the moss-draped trunk of a hardwood tree, the aye-aye ( Daubentonia madagascariensis ) surveys its arboreal domain through wide, unblinking amber eyes. With large, membranous ears that rotate independently like parabolic receivers, the creature listens to sounds completely inaccessible to human ears: the subtle, rhythmic chewing of wood-boring beetle grubs buried several centimeters beneath dense timber. For centuries, the aye-aye defied standard zoological categorization. Early Western naturalists struggled to determine whether this nocturnal creature was an eccentric squirrel, a bizarre rodent, or a primitive primate. Its combination of continuously growing incisors, bushy fox-like tail, bat-like auditory pinnae, and startlingly thin, wire-like digits represents one of the most radical departu...