Lumbricus terrestris

Also known as Nightcrawler, Dew Worm, Lob Worm, Rainworm

Common earthworms construct permanent vertical burrows extending deep into the subsoil, surfacing at night to pull fallen leaves down into their tunnels. As key ecosystem engineers, they aerate dense soil, improve water infiltration, and accelerate the decay of plant litter into nutrient-rich humus. In regions glaciated during the last Ice Age, introduced populations can dramatically alter forest floor dynamics by consuming leaf litter too quickly.