This past weekend, we lost a beloved pet. Shou, a little gray mouse named for the Taoist god of longevity, joined our mixed and motley family six months ago along with her two sisters, Fu and Lu. Even from the beginning, she was the obvious Big Sis, bossing around the others, taking it upon herself to obsessively reorganize and redecorate their shared tank, transforming the new house we'd provided them for into a home. She loved playtime, but she was never one to clambered up my arm to perch on my shoulder. She preferred tunneling under blankets and exploring the dark recesses of empty tissue boxes instead. Still, she blessed our lives with such sweet-tempered assertiveness that even in the short six months she was with us, we came to feel like she'd always been a member of our family. She was dearly loved, and she will be deeply missed.