After one in the morning, tiny hoofbeats dot the asphalt as a soft clatter of manhole lids joins in. They travel in lines of two to five, with the lead sniffing the wind to read the flow of damp air. The second tilts the lid on its back, flashing back the streetlight as a signal. On rainy nights after the storm, they rake fallen leaves into the gutters with noses and forepaws like closing staff at a shop. One courier said that just before a tunnel, when his bike light suddenly died, two large eyes aligned ahead and cast a faint glow only at his feet. The eyes look like crystal, but they seem to gather the city’s reflections and dim automatically when the light turns red. As dawn begins, the herd returns behind park fountains or to the corners of underground garages, props their back lids against the wall, and grooms. Parents teach their young to fold a receipt corner into a neat triangle, giving a gentle bonk if they fumble. Sometimes their playfulness goes too far and they spin a lid so much that neighborhood cats end up dizzy. They rarely harm people and instead help the city breathe by straightening misaligned covers and clearing clogged drains. Photos often fail as the lid’s reflection throws off focus, though a clear shot is said to be possible if you stand a can of coffee on the gutter’s edge.