In Animal Crossing New Horizon Treasure Island, codes don't have an expiration date. If, for some reason, the code doesn't work, it means you redeem it incorrectly.

Animal Crossing: New Leaf for 3DS at IGN: walkthroughs, items, maps, video tips, and strategies ...

House centipedes hide under rocks, so in order to catch them you must hit rocks with your shovel. There are no visual clues to a centipede hiding under the ...