Once thought to be a strange kind of fungi, slime moulds are now recognised as being entirely unrelated. Their classification is still in dispute, but they are generally placed in the Kingdom Protozoa. Slime moulds begin life as simple single-celled amoeboid organisms which are free-living and feed by ingestion of bacteria and fungi. When feeding conditions are good, and when they encounter suitable mating partners, these coalesce into a plasmodium stage of interconnecting strands. In larger slime moulds, these masses often form colourful coatings on vegetation and fallen timber, which observers usually see in the autumnal months. This plasmodium stage of a slime mould is usually able to move, slowly oozing over the substrate and feeding on it. When the food source runs out the spore-producing stages appear.