Eisenia fetida (older spelling: foetida), known under various common names such as redworm, brandling worm, panfish worm, trout worm, tiger worm, red wiggler worm, red californian earth worm, etc., is a species of earthworm adapted to decaying organic material. These worms thrive in rotting vegetation, compost, and manure; they are epigean. They are rarely found in soil, instead preferring conditions that are inimical to some other worms. In this trait they resemble Lumbricus rubellus.