Why do worms come out when it rains? FacebookTwitterLinkedInPinterestStumbleuponEmail Share A Why do worms come out when it rains? Moist, oxygen-poor soil causes earthworms to come to the surface so they can breathe. If you have ever seen worms on a sidewalk after it rains, then it is because they are trying to escape being waterlogged from the rain filling the soil. Permalink Back to Top